• Physics agenda 2017/2018

8/22

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

A few rules and regulations

Reminders-metric system

1. 100 cm = 1 m
2. 1000 m = 1 km
3. 1000 mm = 1 m
4. 106 mm = 1 m
5. 109 nm = 1 m

Complete the following conversions:

1. 45 cm = ___________m
2. 343 g = ___________ kg
3. 1.4 km = __________ m
4. 300 ml = __________ L

Reminders-algebra

Given:  D = m/v   solve for v                                         solve for m

Assignment-algebra and SI activity

8/23

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Go over some sample algebra problems:

1. vf2 =vi2 +2ad                 solve for a

1. a = (vf-vi)/t                   solve for vi

assignment-complete the SI activity from last class and turn in-students may complete at home

assignment-review ws

test on September 2-math review test

8/24

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Turn in the SI activity

Notes:

Solve the following using DA.

1. Water drips from a faucet into a flask at the rate of two drops every 3 seconds.  A cubic centimeter contains 20 drops.  What volume of water, in liters, will be collected in an hour?

1. NASA is going to launch the space shuttle.  They would like to have the shuttle in a 6 km orbit.  How far is this in miles?  (1 m = 3.81 ft,  5280 ft = 1 mi).

1. 898 cm = ___________ m   3.5   400 g = _____________ kg                     3.6  0.7 km = ________ m

1. 898 cm2 = _______________ m2

1. 898 cm3 = _______________ m3

Solve the following.  Make sure you show work and write down each formula that is used.

1. If the room has a length of 17.1 m, a width of 8 m and a height of 3 m, what is the volume of the room?  What is the mass?   The air in the room has a density of 1.15 g/cm3.

1. You measure a cube, and find a side is 4 cm long. The cube has a mass of 500 g.    Find the volume of the cube, and the density of the material that makes up the cube.

Notes:  metric conversions

Assignment-metric conversions-one side

Assignment-algebra review ws

Assignment-work on the math review ws-due September 2

Test on September 2

8/25

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Turn in metric conversions

Alg. Ws

Work on math review

Math review Test on September 2

8/26

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Lab-Find the mass of the air in the room

Compare your mass to the mass of the air in the room.  Make a hypothesis on which is greater.                  Determine a procedure to find the mass of the air in the room with the tools available.

Math review test and review ws due on September 2

8/29

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Metric conversions assignment

Interesting science story

Math/science and its importance in the job market

8/30

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Class given to work on the review ws and ask questions

8/31

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Math, algebra, DA, metric conversions assignment (basically another review)

Test-Sept. 2

Review ws due on Sept. 2

9/1

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Kahoot review

9/2

Test-math review

9/6

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Notes-velocity

• Velocity
• Linear Motion

Motion is relative.  Example : Is your book moving?

Frame of Reference- point at which a position is determined.

Position is the separation between an object and a reference point. Displacement is the change in position.

Displacement-the measurement of how far an object is from its original starting point.  “Distance with direction.”  Displacement is a vector

Distance- amount of separation between two objects. Distance does not include direction, it is a scalar.

Vectors-  quantity that has magnitude and direction

Scalar- quantity that has just magnitude.

• Speed and Velocity
• Speed and Velocity

Speed- distance traveled divided by the time interval during which motion occurred.

Speed measurements involve distance and time

Constant speed is speed that does not change

Speed is calculated by the formula:

Speed = Distance / Time

Velocity is a vector quantity of speed and must have a direction.  Example 40 km/hr West

• Speed and Velocity

Speed- measure of how fast something is moving.  ( scalar ) Formula:  S=d/t

Velocity- change of position divided by the time interval.  (vector) Formula: V = d/t

Instantaneous Speed – speed at any instant

Ex.  Car on a highway entrance

Average Velocity- total distance divided by the total time.  Formula :

• Speed and Velocity cont’d

Constant velocity – constant speed and a constant direction.  Non circular constant speed.

Changing Velocity- changing of speed, direction or both.

• Velocity example problems
• You attempt to catch a crazy ant. It runs at a speed of 0.8 m/s.  How far did it go in 3 seconds?
• A toy remote control car travels 30 cm in 12 seconds. What is its velocity (in cm/s)?  In m/s?  In km/hr?
• Acceleration
• Acceleration-the rate at which velocity is changing. Acceleration = change in velocity / time
• An object is accelerating if its speed is changing, or its direction is changing (or both).
• Examples: a car is traveling in a straight line at a constant speed.  Is it accelerating?
• A plane is traveling in a circle at a constant speed. Is it accelerating?

Intro to velocity ws

9/7

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Acceleration notes

• Physics I
• Acceleration
• Acceleration
• Acceleration occurs when there is a change in speed and/or a change in direction. Or, in other words, acceleration is a change in velocity over a time period
• An object going at a constant speed in a straight line has a constant velocity and an acceleration of zero
• Average Acceleration
• Change in velocity divided by the change in time.
• Formula: Avg. Acc. = v2 - v1 / t2 - t1
• Units: meters /seconds/seconds or m/s2
• Example: The velocity of a car increases from 2.0 m/s at 1.0 s to 16 m/s at 4.5 s. What is the average acceleration?
• Example 2
• A car goes faster and faster backwards down a long driveway. The car’s velocity changes from –2 m/s to –9 m/s in a 2.0 s time interval. Find the acceleration.
• Average and Instantaneous Acceleration
• Average acceleration is also equal to the slope of a velocity-time graph.
• Acc. = rise / run or rv / rt
• Instantaneous Acceleration is the slope of the tangent of the curve at that given time.
• Velocity of an Object with Constant Acceleration

Equation:             vf = vi + at

Final velocity is equal to initial velocity plus acceleration multiplied by time.

*acceleration must be constant*

Ex.  If a car with a velocity of 2 m/s at t = 0 accelerates at a rate of + 4m/s2 for 2.5 s, what is its velocity at t = 2.5 s?

• Displacement during Constant Acceleration
• displacement is the total area under a curve in a velocity/time graph.

Equation:             d = ½ (vf  +  vi) t

Displacement(distance) = ½ the sum of velocity final and velocity initial times the time.

*Acceleration must be constant

Example: What is the displacement of a train as it is accelerated uniformly from + 11 m/s to + 33 m/s in a 20 s interval?

• Displacement when Acceleration and Time are known

If initial velocity, acceleration, and the time interval are known, the displacement of the object can be found by combining equations already used.

Equation:             d = vit + ½ at2

Ex.  A car starting from rest accelerates uniformly at + 6.1 m/s2 for 7 s.  How far does the car move?

• Displacement When Velocity and Acceleration are known

Equation:

v(final)2 = v(initial)2 + 2ad

Ex.  An airplane must reach a velocity of 71 m/s for takeoff.  If the runway is 1 km long, what must the constant acceleration be?

9/8 physics

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Constant acceleration example problem:  A vehicle stars up a hill at 10 m/s.  After 2 s the car reaches the top of the hill with a velocity of 5 m/s.  What is its acceleration?

Assignment- vf = vi + at  ws

9/9

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Turn in vf = vi + at ws

Assignment:  d = ½ (vf + vi) t  ws

9/12

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Turn in d = ½ (vf + vi) t  ws

Example problems-using d =vit + ½ at2 and vf2 = vi2 + 2ad

Example problems-determining which formula to use

Assignment- d =vit + ½ at2 and vf2 = vi2 + 2ad  ws

Quiz coming soon

9/13

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Turn in assignment from last class

Constant acc. Problems

9/14

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Turn in the assignment (lab) from last class

Graphing notes

Graphing activity-graph matching-students will try and match various graphs projected on the screen.  Materials used:  motion detector, and logger pro software--tentative

Test on Sept. 22?

9/15

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Constant acc. WS

Test on Sept. 24

9/16

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Finish and turn in constant acc. Ws from last class

Finish graph notes

Graph ws

Quiz soon-bring your notes

Test on sept. 24

9/19

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Constant acc. Fun problems!

Review sheet

Test on Sept. 24

Quiz on 9/18

9/20

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Quiz

Test on September 24

Review due on Sept. 24

9/21

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Constant acceleration lab with cpo equipment

Assignment-another constant acc. Ws

Work on review

Test 9/26

9/22

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Work on review ws

Test-9/26

Finish and turn in another constant acc. ws

9/23

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Kahoot-1D review

9/26

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

1-D test

9/27

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Notes-acc. Due to gravity

Acc. Due to gravity ws

Pass back graphing ws-go over.  Important concepts are on this assignment and will be on the test

Concepts portion of the test next class

9/28

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

A few reminders about acc. Due to gravity-Be careful about signs!!

Assignment-acc. Due to gravity ws I

9/29

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

More reminders about falling objects-up is +; down is - ; be careful with displacement and velocities!

Review ws-due at the start of class on test day

Reaction time lab

9/30

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Review ws-do it!  Due on the day of the test

Review concepts on acceleration due to gravity

Constant acc. Lab-CPO lab

10/3

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Lab-acceleration due to gravity-CPO lab

Test will probably be on Oct. 8

Reviews due on Oct. 8

Constant acc. 200 ws

Quiz on Oct. 7

10/4

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Finish the acceleration due to gravity lab from last class

Test on Oct. 8

Review due on Oct. 8

Quiz on Oct. 7

10/5

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Lab reminders-Remember units, title, ect. On graphs

Assignment-const acc. 17 ws

Test on Oct. 6

Review due Oct. 6

Kahoot review

10/6

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Test over acceleration caused by gravity

Oct. 7

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Notes-right triangle geometry and vector addition

Find the resultant.

1.  You swim E across the Mississippi river with a velocity of 2 m/s.  The river flows south with a velocity of 8 m/s.  Find your resultant velocity.

1.  You try to swim North (up the Mississippi river) with a velocity of 3 m/s.  The river flows south with a velocity of 8 m/s.  Find your resultant velocity.

1. You run 100 m E and 101 m W. Find your resultant displacement.

Vector addition notes.

1. Add vectors ____________________ to _____________________.
2. Place the resultant from the ___________________of the first vector to the _____________ of the last vector.

Pythagorean theorem =  ________________________________

Assignment-vectors ws

Oct. 11

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Vectors II and more examples

10/12

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Notes-projectiles

• Projectiles-
• A projectile is any object that is in a state of freefall, or in other words an object that is only acted upon by the force of gravity (we are assuming no air resistance in this class!)
• Examples of projectiles
• Projectile motion
• In the absence of air resistance, a projectile will have a constant horizontal velocity and thus a horizontal acceleration of zero (ax = 0)
• The projectile will be accelerated downward by the force of gravity. The vertical acceleration of the projectile will be –9.8 m/s2 (ay = -9.8 m/s2 )
• Projectile motion
• Mr larson is in the cannon
• ***Projectile motion***
• It is important to realize that the horizontal component of projectile motion remains constant.
• Projectile Equations
• Y = Vyit + 1/2at2
• Vyf = vyi + at
• Vyf2 = vyi2 + 2ay
• X =vxit and vxi = vxf ß notice that there is no acceleration.  Why?
• Vyi = visinq
• Vxi = vicos q
• Example
• A cannon is fired horizontally at 20 m/s. Notice what happens to its horizontal velocity and its vertical velocity.
• Example of a horizontally launched projectile
• A cannon is fired horizontally at 20 m/s on a 10 m tall cliff. How long will the cannon ball be in the air?  How far from the base of the cliff will the cannon ball fall?
• Projectile motion
• Compare the horizontal motion of the gravity free path and the projectile motion.
• Compare the vertical motion and the projectile motion.
• Projectile launched at an angle example
• Projectile launched at an angle from ground level
• The raider qb(greg jones) passes a football with a velocity of 3 m/s at an angle of 10 degrees with the ground. How high does the football go?  How long is the football in the air?  How far does the football travel?
• Example problem
• Kristen throws adam off of a cliff that is 15 m high. she throws adam with a velocity of 12 m/s at an angle 33 degrees.  How long is adam in the air?

Assignment-vectors II ws

Oct. 13

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Notes-example problems-projectiles shot horizontally-notes to done in class with the aid of student volunteers.

*Notes-Projectiles thrown horizontally-Notes*

An arrow is shot horizontally with an initial velocity of 80 m/s off of a 20 m high building.  Find the time arrow is in the air and how far away it lands.  Assume no air resistance!

1. Draw a diagram:

1. Write the givens:
1. vi =
2. q =
• ay =
1. vertical components d. horizontal components
2. vyi =                                                                                                   ii.  Vxi =
1. Solve for the maximum time in the air
1. Use this formula: Y = vyit +(1/2)at2

1. Solve for the range
1. Use this formula: X = vxit

1. A North American croc (they are only in Florida) swims E across a river with a velocity of 3 m/s.  The river flows south with a velocity of 7 m/s.  Find its resultant velocity
2. A bird flies with a velocity of 2 m/s.  It encounters a hurricane force wind that is blowing at 50 m/s.  Find the bird’s maximum and minimum resultant velocities.
3. To shoot a projectile as far as possible, it would be shot at an angle of _____________.  To shoot it as high as possible, it would be shot at an angle of _____________.  So that it stays in the air for the longest amount of time, it would be shot at an angle of _____________________.

1. John pushes a snicker’s bar off of a very tall cliff with an initial velocity of 3 m/s.  It hits the ground after 10 seconds.  Find the height of the cliff.   How far away from the base of the cliff did the candy bar land?  Find the vertical velocity of the snicker’s bar at t = 3 seconds.
1. Draw a diagram

1. Write down your givens: vi =            q =                   ay =
1. vertical components                                                     horizontal components
1. vyi = vxi =
2. Solve for the vertical displacement using : Y = vyit +(1/2)at2
2. Solve for how far the candy went using  X = vxit

1. solve for the vertical velocity at t = 3 seconds by using:  vfy = vyi + at

10/14

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Vectors and projectiles ws

Lab-determining the angle to shoot a projectile to get max range.-if time

10/17

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Projectiles launched at angle ws-currently, the only angles I can cover (this applies to free response-I can still cover concepts) are 0 degrees, 180 degrees, 90 degrees (straight up), and straight down.

Lab-projectiles lab-finding the angle to get max range

10/17

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Projectile simulation lab

Projectiles-3 questions

10/18

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Projectiles-questions and concepts

Projectile  lab-horizontal shot

Quiz next class

10/19

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Quiz-projectiles

Test –Oct. 24

10/20

Review questions

Begin forces notes

Test-Free response next class

Test –Oct. 24

10/21

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Kahoot review

Test next class

Review due next class

Oct. 24

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Test-2D motion, vectors and projectiles

10/29

10/25

Goal:  the student will understand the relationship between Force and acceleration and mass and acceleration.

Goal: the student will be able to solve for various forces, and acceleration.

Begin forces notes

Notes-forces

• Forces

Force- a push or pull

Gravitational force- force between all objects.  Any mass exerts a force upon any other mass

Electromagnetic force- forces between charged particles.

Strong Nuclear force- holds particles in nucleus of an atom together. (strongest)

Weak force- a form of electromagnetic force from radioactive decay.

• Newton’s 1st Law of Motion

Otherwise known as Newton’s Law of Inertia

States:  an object with no force acting on it remains at rest or moves with constant velocity in a straight line.

Inertia:  the tendency of an object to resist a change in its state of motion.  Inertia is dependent upon mass.

• Newton’s 1st Law
• In other words,
• Newton’s 1st law: an object at rest will stay at rest and an object in motion will stay in motion at a constant velocity in a straight line unless acted upon by an outside force.
• Newton’s 2nd Law of Motion

Force = Mass x Acceleration

Units: Newton’s

Newton =  kg m/s^2

Newton’s 2nd law is also known as the law of acceleration

• Newton’s 2nd law

Problem:

What net force is required to accelerate a 1500 kg race car at 3 m/s2?

• Newton’s 3rd Law of Motion

When one object exerts a force on a second object, the second exerts a force on the first that is equal in magnitude but opposite in direction.  For every action there is an opposite and equal reaction.

Action-Reaction

• Mass and Weight

Weight is the gravitational force exerted by the earth.

Weight = Mass x Acceleration due to Gravity

Ex.  Find the weight of a 2.3 kg bag of sugar.

• Friction

The force that opposes motion between two surfaces that are in contact.

Static Friction – the force that opposes the start of motion.  Ex. Pushing a box

Sliding Friction – the force between surfaces in relative motion.  Sliding friction is also called kinetic friction.  Ex. Pushing a box

• Net Forces

The net force is the vector sum of all forces acting on a body.

The acceleration of an object is always in the same direction as the net force.

Air resistance to falling objects is called drag.

Terminal velocity – when the drag force equals the force of gravity.  Do you know the terminal velocity for the average person?

• Questions
• Question #2-3
• Caitlin, mass = 58 kg, is going sky diving. Air resistance provides a lift of 60 N.  Find the net force acting on her and her acceleration.
• A 2 kg object has an acceleration of 10 m/(ss) to the right. A force of 5 N acts on it towards the left.  Find the net force acting on the object and what force must be acting towards the right.
• Friction Continued

Coefficient of Friction – a constant that depends upon the 2 surfaces in contact.

The higher the coefficient of friction, the greater the frictional force will be between the two surfaces

Equation:                             Ff = µ Fn

Force of Friction = Coefficient of Friction x

Normal force (perpendicular force)

• Problem Solving
1. Sketch the drawing
2. Draw the arrows representing the forces
3. Label each arrow with the force it is representing.  Be Specific!
• Example Problems

Ex.  Elevator

Fnet =  Fapplied +  Wt.

Net force is equal to the sum of the applied force + the weight.

Example:   A spring scale hangs from the ceiling of an elevator. It supports a package that weighs 25 N.  A) what is the upward force the scale exerts when the elevator is not moving?  B) what force must the scale exert to accelerate the package 1.5 m/s2?

Oct. 26

Goal:  the student will understand the relationship between Force and acceleration and mass and acceleration.

Goal: the student will be able to solve for various forces, and acceleration.

Finish Forces notes

Friction Notes:

## Friction Notes

____________________ is the force that tends to __________________ the motion between two surfaces in contact.  It acts __________________ to the direction of motion.

Static friction (Fs) is the force that _________________ the start of motion.  As long as the object does not move, the static friction is _____________ to and opposite to the force applied.  For example, David pushes a M1 Abrams tank with a force of 900 N.  The tank remains stationary.  The force of static friction acting against the object’s motion is _____________________.  In other words, Fs = - Fapplied or –Fs = Fapplied .

Examples:  Find Fs for the following stationary objects:

Eventually, the applied force on the object will exceed Fs max (the max static friction) and the object will _________________.  When solving any problems, we will assume that Fs max = Fapplied (or that the maximum static friction is equal to the force applied).

The force between surfaces in relative motion is called ___________________ friction.  Sliding friction is also known as kinetic friction (Fk).  Sliding friction _______________ the motion of two contacting surfaces that are moving past one another.  The force of sliding friction between two objects is less than the force of static friction between two objects.  For example, you try to push a very large and heavy box across the room.  It will take (more or less) effort to get it to move, but once you get it moving it is (easier or harder) to keep it moving.

The normal force (Fn):  A force exerted by one object on another object in a direction that is perpendicular to the surface of contact.  The normal force is equal and opposite to the component of an object’s ____________ that is perpendicular to the contact surface.

Examples.  Find Fn :

Through experimentation, it has been found that the force of friction (Ff) depends primarily upon the ___________________ force and the types of surfaces in contact.

The force of friction can be solved using the following equation:

Where Ff is the _________________________

Fn is the ____________________________

And m is the coefficient of friction.

Example problems:

A force of 30 N is required to just move a stationary 1 kg crate.  What is the normal force?  What is the coefficient of friction between the crate and the floor?

Sara attaches a spring scale to a 1 kg book and pulls it across the floor with a constant velocity.  The spring scale has a reading of 10 N.  What is the normal force?  What is the coefficient of friction between the book and the floor?

Oct. 27

Goal:  the student will understand the relationship between Force and acceleration and mass and acceleration.

Goal: the student will be able to solve for various forces, and acceleration.

Finish friction notes

Ex. Credit project info:

1. Extra assignmnentNewton's Laws T-Shirt -
Due November8-16  except for November 14,16 test days.  Extra Test Grade -  You must decorate a T-shirt so that it illustrates one of Newton's Three Laws of Motion.  The T-Shirt must contain one of the three laws, it's definition, a picture or illustration of the law and your name.  The T-shirt must be done neatly and should cover most of it(Front and Back).  You must wear the T-shirt on all day when you present the T-shirt in front of the class.  You may work in groups of 3 but each member of your group will need to cover a different law -- you need one t-shirt per group member -- (students in groups need to be in the same class period).  Points possible will be out of 30 points.  Those T-shirts that go above and beyond the minimum standards can earn more than 30 points with a maximum grade of up to 33 points. Staples, paper and tape are not permitted on T-Shirts.  Also, please do not write with pen or pencil.  T-shirts that contain Staples, Tape, Paper, and are written in Pen or Pencil will not be graded.  YOUR NAME MUST BE ON YOUR SHIRT.

Spring Scale challenge

Ff ws-

Oct. 28

Goal:  the student will understand the relationship between Force and acceleration and mass and acceleration.

Goal: the student will be able to solve for various forces, and acceleration.

Notes-Convert your weight in LBS to N.  Given:  2.21 LBS = 1 kg

Friction lab-students will determine the coefficient of friction between their physics book and various surfaces.

1. Extra assignmnentNewton's Laws T-Shirt -
Due November 15  except test days.  Extra Test Grade -  You must decorate a T-shirt so that it illustrates one of Newton's Three Laws of Motion.  The T-Shirt must contain one of the three laws, it's definition, a picture or illustration of the law and your name.  The T-shirt must be done neatly and should cover most of it(Front and Back).  You must wear the T-shirt on all day when you present the T-shirt in front of the class.  You may work in groups of 3 but each member of your group will need to cover a different law -- you need one t-shirt per group member -- (students in groups need to be in the same class period).  Points possible will be out of 30 points.  Those T-shirts that go above and beyond the minimum standards can earn more than 30 points with a maximum grade of up to 33 points. Staples, paper and tape are not permitted on T-Shirts.  Also, please do not write with pen or pencil.  T-shirts that contain Staples, Tape, Paper, and are written in Pen or Pencil will not be graded. YOUR NAME MUST BE ON YOUR SHIRT.

Oct. 28

Goal:  the student will understand the relationship between Force and acceleration and mass and acceleration.

Goal: the student will be able to solve for various forces, and acceleration.

Net force notes-example problems

Net force ws

11/10

Net force example problems

Work on net force ws

11/11

Lab-Newton’s 3 Laws lab-students will construct balloon rockets and race them across the room.  Students will make at least one observation of each of Newton’s 3 laws.

Shirt project due on Dec. 1

*CD 4-1

*Newton’s laws review

11/12

Newton’s laws review

1. Extra assignmnentNewton's Laws T-Shirt -
Due November 15 except for.  Extra Test Grade -  You must decorate a T-shirt so that it illustrates one of Newton's Three Laws of Motion.  The T-Shirt must contain one of the three laws, it's definition, a picture or illustration of the law and your name.  The T-shirt must be done neatly and should cover most of it(Front and Back).  You must wear the T-shirt on all day when you present the T-shirt in front of the class.  You may work in groups of 3 but each member of your group will need to cover a different law -- you need one t-shirt per group member -- (students in groups need to be in the same class period).  Points possible will be out of 30 points.  Those T-shirts that go above and beyond the minimum standards can earn more than 30 points with a maximum grade of up to 33 points. Staples, paper and tape are not permitted on T-Shirts.  Also, please do not write with pen or pencil.  T-shirts that contain Staples, Tape, Paper, and are written in Pen or Pencil will not be graded. YOUR NAME MUST BE ON YOUR SHIRT.

11/13

Review-kahoots?

Work on review

11/14

Turn in review and all late forces assignments

Test-froces workout problems and

concepts  on Nov. 18

11/17

Notes-Uniform circular motion

Assignment-uniform circular motion intro ws

Review for forces test

11/18

Forces concepts test

Turn in review ws

11/19

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Finish notes on uniform circular motion

• Uniform Circular Motion
• An object going in a circle at a constant speed.
• Question: is an object that is undergoing uniform circular motion accelerating?
• rotation
• rotation: when an object spins or rotates around an internal axis.  Example:  A krispy kreme rotating around a straw.
• Revolution
• revolution: when an object turns or revolves around an external axis.  Example:  A planet revolving around a star.
• Linear speed and tangential speed
• linear speed: distance moved per unit of time (speed).
• tangential speed (Vt) : the speed of an object that is moving along a circular path.  The direction of motion is tangent to the circle.
• Angular speed, force, period
• angular speed (w): the number of rotations per unit of time. Also called rotational speed.
• centripetal force (Fc): any force that will cause an object to take a circular path.
• period: the time for one revolution
• Frequency and period
• Frequency: number of revolutions (turns) per time unit (usually seconds).
• Frequency: number of events/time
• The frequency and period are reciprocals of each other
• Key Points for Uniform Circular Motion
• All points on a rotating rigid object will have the same angular speed (and thus the same angular acceleration).
• The tangential speed of an object placed on a rotating body will increase as it is moved away from the center of the rigid body.
• An object that is following a circular path has a net force (Fc) and acceleration (ac) that are acting towards the center of the object.
• Key points continued
• Velocity is always tangent to the circle and is always changing.
• Acceleration goes
• towards the center of
• the circle
• Look at the following rotating disk. Which point has the greater tangential velocity?  Which point has the greater angular velocity?
• Formulas
• Equations:
• ac = vt2                                 Fc = mac = mvt2
•   r                                                                            r
• vt = rw ß  w must be in radians per time unit
• Ac = rw2
• Reminders:
• 1 revolution = 360 degrees = 2 p rad
• for one revolution v = d =    2 p r
• t                 T

11/20

Review Force of friction and normal force

Shirt project presentations

11/21

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Assignment-circular motion ws I

Notes-Uniform circular motion

examples

12/1

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Notes-circular motion example problems:

Circular motion Example Problems

1. A queen Pogonomyrmex, m = 100 g, is flying around a 50 cm circular path. She experiences a force of 2 N acting towards the center of the flight path.  Find the ant’s tangential speed.
2. An F-22 raptor, m = 19, 700 kg, is flying at 400 m/s in a circular path with a radius of 1 km. Find the centripetal force acting on the raptor.
3. A great white shark circles a prey item with a leisurely speed of 4 m/s. The large shark has a centripetal acceleration of 0.5 m/s2.  The shark has a mass of 1000 kg.  Find radius of motion.
4. A 500 g bird makes two complete revolutions in 4 seconds with a diameter of 110 cm.
5. find the period
6. Find the frequency of motion
7. The tangential speed in cm/sec and m/sec
8. The centripetal acceleration in cm/sec2 and m/sec2
9. The centripetal force acting on the bird

Look at the following doughnut.  Assume that the tasty pastry is rotating at a constant rate.  The three dots represent ants that are riding the doughnut like a merry-go-round.

1. Which ant will have the greatest tangential speed? Explain.
2. Which ant will have the greatest linear speed? Explain.
3. Which ant will have the greatest centripetal force? Explain.
4. If the force of friction was no longer great enough to hold ant C on the doughnut, how would it fly off?

Go over a couple of problems from the circular motion I ws

12/2

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Warm up on board-complete on your own paper

Warm up àAn object is placed 5 m from the center of a rotating disk.  The object has a tangential speed of 10 m/s.  A force of 20 N is required to keep the object going in a circle.   Find:  a) radius b)  diameter c) linear speed d) centripetal force   e) mass of the object

Review the following terms:

Period

Frequency

Tangential speed

Centripetal acceleration

Centripetal force

Centripetal force vs centrifugal force

Critical velocity

Circular motion bird ws

Test on Dec. 10

12/3

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Warm up:  on board

12/4

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Circular motion lab

12/5

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Warm up:

Uniform circular motion-warm up

A hollow toy airbus 380 is attached to the ceiling with string.  An ant is riding in the pilot’s seat.  The plane is traveling in a circle that has a diameter of 200 cm.  The air bus makes 20 revolutions in 40 seconds.  The toy plane has a mass of 100 g.

What is the frequency of the plane?

What is the period of the plane?

What is the linear speed of the plane (in m/s)?

What is the acceleration of the plane (in m/s2)?

What is the centripetal force?

What is the direction of the centripetal force acting on the plane?

What is the direction of the centripetal acceleration?

What object provides the centripetal force to the plane?

What provides the centripetal force to the ant?

If the string breaks, how will the plane fly off?

Circular motion II ws

Quiz on Dec. 9

Test on Dec. 10

12/8

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Warm up:

Warm up-circular motion

A toy 200 g bird is attached to the ceiling with a string.  With a gentle push and turning on the “on” button, the bird flies in a circle that has a radius of 100 cm.  The bird completes 10 revolutions in 30 seconds.

Find the frequency of the toy bird in Hz

Find the period of the toy bird in sec.

Solve for the linear speed of the bird in m/s

Step 1:  convert the bird’s flight radius into meters.  100 cm = _________ m.

Step 2:  realize that I do not have enough information to use the following formulas with linear speed:    F =(mv2)/r                                a = v2/r

Step 3:  Understand that I have the period (T) and the radius (r) of the bird and with that I can use

v = ______________.   Since you are solving for the velocity in m/s, the radius should be in _________.

Step 4.  Solve for the linear speed.

Solve for the acceleration of the bird in m/s.

Step 1:  Determine which formula you should use.  You have the radius (r) of the bird and the linear speed of the bird (v).  You want to solve for the acceleration (a).  The formula that you must use has all three of these variables (a, v, r).

Step 2:  write down the formula.  The formula that you are using is a = _________________.

Step 3:  solve for a.  Make sure that your radius is in m and your velocity is in m/s.

Find the centripetal force acting on the bird in Newtons.

Step 1:  convert the mass in grams to kg.  200 g = _____________ kg.

Step 2:  Choose your formula.  You must pick a formula that has force in it.  Some wise choices:

F = ma                   or           F = (mv2)/r

Make sure that your mass is in __________ and your radius is in __________.

Step 3.  Solve for the force.

A humming bird’s wings have a frequency of 200 Hz.  Find the period.

Matt spins a 100 g ball in a circle with a radius of 50 cm.  Find the critical velocity that he needs to spin it with.

Kim and Kelsey sit 2 m from the center of a merry-go-round.  They have a centripetal acceleration of 8 m/s2.  Find their linear speed.

Review ws

Finish circular motion II ws

Quiz next class

Test Dec. 10 and quiz Dec. 9

12/9

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Circular motion quiz -notes are allowed?

Test Dec. 10

Review due on test day

12/10

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Circular motion test today

Review due today

12/11

Notes-Newton’s Laws of Universal Gravitation

• Universal Gravitation and Kepler’s Laws
• Keplers 1st Law of Planetary Motion
1. The paths of the planets are ellipses with the center of the sun at one focus.
• Kepler’s 2ndLaw of planetary motion
1. An imaginary line from the sun to a planet sweeps out equal areas in equal time intervals.  Thus, planets move fastest when closest to the sun, and slowest farthest from the sun.

.

• Kepler’s Third Law
• The ratio squares of the periods of any two planets revolving around the sun is equal to the ratio of the cubes of their average distances from the sun
• Kepler’s Laws cont’d

Equation:  (Ta/Tb)2 = (ra/rb)3

Planet A’s period divided by planet B’s period squared = average distance of A divided by the average distance of B cubed.

Ex.  Galileo discovered 4 moons on Jupiter.  Io which he measured to be 4.2 units from the center of Jupiter has a period of 1.8 days.  He measured the radius of Ganymede’s orbit as 10.7 units.  Use Kepler’s 3rd Law to find the period of Ganymede.

• Newton’s Law of Universal Gravitation

The gravitational force between any 2 bodies varies directly as the product of their masses and inversely as the square of the distance between them.  Also called the inverse square law.

Equation:  F= G m1m2/d2

Force equals Universal constant x mass of body 1 x mass of body 2 / distance squared

• Example Problem UG
• A 2 kg mass is at rest on the surface of the Earth. Find the force of attraction that exists between the mass and Earth.  The radius of Earth is 6.4 x 10^6 m.  The mass of earth is 6 x 10^24 kg.
• Motion of Planets and Satellites

To solve for the velocity of a satellite the equation is :     v = (square root of) Gme/r

The time for the satellite to orbit the earth is the period or T.

Equation:             T = 2P (square root of ) r3/Gme

Acceleration of gravity Calculated:

a= g(Re/d)2

• Universal Gravitation Example Problems
• What happens to the force of attraction if one mass is doubled?
• What happens to the force of attraction if the distance between the two objects is doubled?
• What happens to the force of attraction if both masses are doubled and the distance is tripled?
• Q
• Questions
• What force holds the planets in orbit around the sun?
• What would happen to the planets if this force was insufficient, or the velocities of planets increased greatly?

UG ws

Quiz on Monday?

Project info-due Friday-highly tentative

On your semester exam you may use one 3x5 note card.  Hand written on the front and the back.

12/12

Example problems/warm up

Universal Gravitation Example Problems and Warm  up

Givens:  mE = 6 x 1024 kg                         rE = 6.4 x 106 m                       mmars = 6.4 x 1023 kg

Distance between Earth and Mars = 8 x 1010 m

Example problems.

1. The force of attraction between a small cat and the planet Earth is 49 N.  Find the mass of the cat (it is safe to assume that the cat is in Earth)
2. What would happen to your weight if:
1. Your mass doubled
2. The radius of Earth increased 5 times
3. The mass of the Earth doubled and you the radius of earth increased 4 times

Warm up

1. Find the force of gravity between a gigantic 2 kg hamburger and the Earth.

1. The force of attraction between the Earth and a 1000 kg orbiting satellite is 10 N.  Find the distance between the Earth and the satellite.

1. What would happen to the force of attraction between two objects if
1. One mass is doubled and one mass is tripled
2. One mass is increased 4 times and the distance between them is doubled

Finish UG WS and turn in

Work on the project!

Quiz on Thursday or Monday (probably Thursday)

12/15-12-19

Review ws for the semester exam-you may use one 3x5 note card on the semester exam.  Hand written!

Work on review and make your 3x5 note card

Semester Exams!

Physics agenda 2014/2015

8/22

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

A few rules and regulations

Reminders-metric system

1. 100 cm = 1 m
2. 1000 m = 1 km
3. 1000 mm = 1 m
4. 106 mm = 1 m
5. 109 nm = 1 m

Complete the following conversions:

1. 45 cm = ___________m
2. 343 g = ___________ kg
3. 1.4 km = __________ m
4. 300 ml = __________ L

Reminders-algebra

Given:  D = m/v   solve for v                                         solve for m

Assignment-algebra and SI activity

8/23

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Go over some sample algebra problems:

1. vf2 =vi2 +2ad                 solve for a

1. a = (vf-vi)/t                   solve for vi

assignment-complete the SI activity from last class and turn in-students may complete at home

assignment-review ws

test on September 2-math review test

8/24

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Turn in the SI activity

Notes:

Solve the following using DA.

1. Water drips from a faucet into a flask at the rate of two drops every 3 seconds.  A cubic centimeter contains 20 drops.  What volume of water, in liters, will be collected in an hour?

1. NASA is going to launch the space shuttle.  They would like to have the shuttle in a 6 km orbit.  How far is this in miles?  (1 m = 3.81 ft,  5280 ft = 1 mi).

1. 898 cm = ___________ m   3.5   400 g = _____________ kg                     3.6  0.7 km = ________ m

1. 898 cm2 = _______________ m2

1. 898 cm3 = _______________ m3

Solve the following.  Make sure you show work and write down each formula that is used.

1. If the room has a length of 17.1 m, a width of 8 m and a height of 3 m, what is the volume of the room?  What is the mass?   The air in the room has a density of 1.15 g/cm3.

1. You measure a cube, and find a side is 4 cm long. The cube has a mass of 500 g.    Find the volume of the cube, and the density of the material that makes up the cube.

Notes:  metric conversions

Assignment-metric conversions-one side

Assignment-algebra review ws

Assignment-work on the math review ws-due September 2

Test on September 2

8/25

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Turn in metric conversions

Alg. Ws

Work on math review

Math review Test on September 2

8/26

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Lab-Find the mass of the air in the room

Compare your mass to the mass of the air in the room.  Make a hypothesis on which is greater.                  Determine a procedure to find the mass of the air in the room with the tools available.

Math review test and review ws due on September 2

8/29

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Metric conversions assignment

Interesting science story

Math/science and its importance in the job market

8/30

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Class given to work on the review ws and ask questions

8/31

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Math, algebra, DA, metric conversions assignment (basically another review)

Test-Sept. 2

Review ws due on Sept. 2

9/1

Goal: review/refresh concepts that were previously learned.  Focus on metric system, DA, measurement, and algebra.

Kahoot review

9/2

Test-math review

9/6

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Notes-velocity

• Velocity
• Linear Motion

Motion is relative.  Example : Is your book moving?

Frame of Reference- point at which a position is determined.

Position is the separation between an object and a reference point. Displacement is the change in position.

Displacement-the measurement of how far an object is from its original starting point.  “Distance with direction.”  Displacement is a vector

Distance- amount of separation between two objects. Distance does not include direction, it is a scalar.

Vectors-  quantity that has magnitude and direction

Scalar- quantity that has just magnitude.

• Speed and Velocity
• Speed and Velocity

Speed- distance traveled divided by the time interval during which motion occurred.

Speed measurements involve distance and time

Constant speed is speed that does not change

Speed is calculated by the formula:

Speed = Distance / Time

Velocity is a vector quantity of speed and must have a direction.  Example 40 km/hr West

• Speed and Velocity

Speed- measure of how fast something is moving.  ( scalar ) Formula:  S=d/t

Velocity- change of position divided by the time interval.  (vector) Formula: V = d/t

Instantaneous Speed – speed at any instant

Ex.  Car on a highway entrance

Average Velocity- total distance divided by the total time.  Formula :

• Speed and Velocity cont’d

Constant velocity – constant speed and a constant direction.  Non circular constant speed.

Changing Velocity- changing of speed, direction or both.

• Velocity example problems
• You attempt to catch a crazy ant. It runs at a speed of 0.8 m/s.  How far did it go in 3 seconds?
• A toy remote control car travels 30 cm in 12 seconds. What is its velocity (in cm/s)?  In m/s?  In km/hr?
• Acceleration
• Acceleration-the rate at which velocity is changing. Acceleration = change in velocity / time
• An object is accelerating if its speed is changing, or its direction is changing (or both).
• Examples: a car is traveling in a straight line at a constant speed.  Is it accelerating?
• A plane is traveling in a circle at a constant speed. Is it accelerating?

Intro to velocity ws

9/7

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Acceleration notes

• Physics I
• Acceleration
• Acceleration
• Acceleration occurs when there is a change in speed and/or a change in direction. Or, in other words, acceleration is a change in velocity over a time period
• An object going at a constant speed in a straight line has a constant velocity and an acceleration of zero
• Average Acceleration
• Change in velocity divided by the change in time.
• Formula: Avg. Acc. = v2 - v1 / t2 - t1
• Units: meters /seconds/seconds or m/s2
• Example: The velocity of a car increases from 2.0 m/s at 1.0 s to 16 m/s at 4.5 s. What is the average acceleration?
• Example 2
• A car goes faster and faster backwards down a long driveway. The car’s velocity changes from –2 m/s to –9 m/s in a 2.0 s time interval. Find the acceleration.
• Average and Instantaneous Acceleration
• Average acceleration is also equal to the slope of a velocity-time graph.
• Acc. = rise / run or rv / rt
• Instantaneous Acceleration is the slope of the tangent of the curve at that given time.
• Velocity of an Object with Constant Acceleration

Equation:             vf = vi + at

Final velocity is equal to initial velocity plus acceleration multiplied by time.

*acceleration must be constant*

Ex.  If a car with a velocity of 2 m/s at t = 0 accelerates at a rate of + 4m/s2 for 2.5 s, what is its velocity at t = 2.5 s?

• Displacement during Constant Acceleration
• displacement is the total area under a curve in a velocity/time graph.

Equation:             d = ½ (vf  +  vi) t

Displacement(distance) = ½ the sum of velocity final and velocity initial times the time.

*Acceleration must be constant

Example: What is the displacement of a train as it is accelerated uniformly from + 11 m/s to + 33 m/s in a 20 s interval?

• Displacement when Acceleration and Time are known

If initial velocity, acceleration, and the time interval are known, the displacement of the object can be found by combining equations already used.

Equation:             d = vit + ½ at2

Ex.  A car starting from rest accelerates uniformly at + 6.1 m/s2 for 7 s.  How far does the car move?

• Displacement When Velocity and Acceleration are known

Equation:

v(final)2 = v(initial)2 + 2ad

Ex.  An airplane must reach a velocity of 71 m/s for takeoff.  If the runway is 1 km long, what must the constant acceleration be?

9/8 physics

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Constant acceleration example problem:  A vehicle stars up a hill at 10 m/s.  After 2 s the car reaches the top of the hill with a velocity of 5 m/s.  What is its acceleration?

Assignment- vf = vi + at  ws

9/9

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Turn in vf = vi + at ws

Assignment:  d = ½ (vf + vi) t  ws

9/12

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Turn in d = ½ (vf + vi) t  ws

Example problems-using d =vit + ½ at2 and vf2 = vi2 + 2ad

Example problems-determining which formula to use

Assignment- d =vit + ½ at2 and vf2 = vi2 + 2ad  ws

Quiz coming soon

9/13

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Turn in assignment from last class

Constant acc. Problems

9/14

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Turn in the assignment (lab) from last class

Graphing notes

Graphing activity-graph matching-students will try and match various graphs projected on the screen.  Materials used:  motion detector, and logger pro software--tentative

Test on Sept. 22?

9/15

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Constant acc. WS

Test on Sept. 24

9/16

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Finish and turn in constant acc. Ws from last class

Finish graph notes

Graph ws

Quiz soon-bring your notes

Test on sept. 24

9/19

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Constant acc. Fun problems!

Review sheet

Test on Sept. 24

Quiz on 9/18

9/20

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Quiz

Test on September 24

Review due on Sept. 24

9/21

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Constant acceleration lab with cpo equipment

Assignment-another constant acc. Ws

Work on review

Test 9/26

9/22

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Work on review ws

Test-9/26

Finish and turn in another constant acc. ws

9/23

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

Kahoot-1D review

9/26

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration.

1-D test

9/27

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Notes-acc. Due to gravity

Acc. Due to gravity ws

Pass back graphing ws-go over.  Important concepts are on this assignment and will be on the test

Concepts portion of the test next class

9/28

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

A few reminders about acc. Due to gravity-Be careful about signs!!

Assignment-acc. Due to gravity ws I

9/29

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

More reminders about falling objects-up is +; down is - ; be careful with displacement and velocities!

Review ws-due at the start of class on test day

Reaction time lab

9/30

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Review ws-do it!  Due on the day of the test

Review concepts on acceleration due to gravity

Constant acc. Lab-CPO lab

10/3

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Lab-acceleration due to gravity-CPO lab

Test will probably be on Oct. 8

Reviews due on Oct. 8

Constant acc. 200 ws

Quiz on Oct. 7

10/4

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Finish the acceleration due to gravity lab from last class

Test on Oct. 8

Review due on Oct. 8

Quiz on Oct. 7

10/5

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Lab reminders-Remember units, title, ect. On graphs

Assignment-const acc. 17 ws

Test on Oct. 6

Review due Oct. 6

Kahoot review

10/6

Goal:  the student will be able to solve for time, acceleration, displacement, and various velocities.

Goal:  the student will understand the concept of acceleration and acceleration caused by gravity.

Test over acceleration caused by gravity

Oct. 7

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Notes-right triangle geometry and vector addition

Find the resultant.

1.  You swim E across the Mississippi river with a velocity of 2 m/s.  The river flows south with a velocity of 8 m/s.  Find your resultant velocity.

1.  You try to swim North (up the Mississippi river) with a velocity of 3 m/s.  The river flows south with a velocity of 8 m/s.  Find your resultant velocity.

1. You run 100 m E and 101 m W. Find your resultant displacement.

Vector addition notes.

1. Add vectors ____________________ to _____________________.
2. Place the resultant from the ___________________of the first vector to the _____________ of the last vector.

Pythagorean theorem =  ________________________________

Assignment-vectors ws

Oct. 11

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Vectors II and more examples

10/12

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Notes-projectiles

• Projectiles-
• A projectile is any object that is in a state of freefall, or in other words an object that is only acted upon by the force of gravity (we are assuming no air resistance in this class!)
• Examples of projectiles
• Projectile motion
• In the absence of air resistance, a projectile will have a constant horizontal velocity and thus a horizontal acceleration of zero (ax = 0)
• The projectile will be accelerated downward by the force of gravity. The vertical acceleration of the projectile will be –9.8 m/s2 (ay = -9.8 m/s2 )
• Projectile motion
• Mr larson is in the cannon
• ***Projectile motion***
• It is important to realize that the horizontal component of projectile motion remains constant.
• Projectile Equations
• Y = Vyit + 1/2at2
• Vyf = vyi + at
• Vyf2 = vyi2 + 2ay
• X =vxit and vxi = vxf ß notice that there is no acceleration.  Why?
• Vyi = visinq
• Vxi = vicos q
• Example
• A cannon is fired horizontally at 20 m/s. Notice what happens to its horizontal velocity and its vertical velocity.
• Example of a horizontally launched projectile
• A cannon is fired horizontally at 20 m/s on a 10 m tall cliff. How long will the cannon ball be in the air?  How far from the base of the cliff will the cannon ball fall?
• Projectile motion
• Compare the horizontal motion of the gravity free path and the projectile motion.
• Compare the vertical motion and the projectile motion.
• Projectile launched at an angle example
• Projectile launched at an angle from ground level
• The raider qb(greg jones) passes a football with a velocity of 3 m/s at an angle of 10 degrees with the ground. How high does the football go?  How long is the football in the air?  How far does the football travel?
• Example problem
• Kristen throws adam off of a cliff that is 15 m high. she throws adam with a velocity of 12 m/s at an angle 33 degrees.  How long is adam in the air?

Assignment-vectors II ws

Oct. 13

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Notes-example problems-projectiles shot horizontally-notes to done in class with the aid of student volunteers.

*Notes-Projectiles thrown horizontally-Notes*

An arrow is shot horizontally with an initial velocity of 80 m/s off of a 20 m high building.  Find the time arrow is in the air and how far away it lands.  Assume no air resistance!

1. Draw a diagram:

1. Write the givens:
1. vi =
2. q =
• ay =
1. vertical components d. horizontal components
2. vyi =                                                                                                   ii.  Vxi =
1. Solve for the maximum time in the air
1. Use this formula: Y = vyit +(1/2)at2

1. Solve for the range
1. Use this formula: X = vxit

1. A North American croc (they are only in Florida) swims E across a river with a velocity of 3 m/s.  The river flows south with a velocity of 7 m/s.  Find its resultant velocity
2. A bird flies with a velocity of 2 m/s.  It encounters a hurricane force wind that is blowing at 50 m/s.  Find the bird’s maximum and minimum resultant velocities.
3. To shoot a projectile as far as possible, it would be shot at an angle of _____________.  To shoot it as high as possible, it would be shot at an angle of _____________.  So that it stays in the air for the longest amount of time, it would be shot at an angle of _____________________.

1. John pushes a snicker’s bar off of a very tall cliff with an initial velocity of 3 m/s.  It hits the ground after 10 seconds.  Find the height of the cliff.   How far away from the base of the cliff did the candy bar land?  Find the vertical velocity of the snicker’s bar at t = 3 seconds.
1. Draw a diagram

1. Write down your givens: vi =            q =                   ay =
1. vertical components                                                     horizontal components
1. vyi = vxi =
2. Solve for the vertical displacement using : Y = vyit +(1/2)at2
2. Solve for how far the candy went using  X = vxit

1. solve for the vertical velocity at t = 3 seconds by using:  vfy = vyi + at

10/14

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Vectors and projectiles ws

Lab-determining the angle to shoot a projectile to get max range.-if time

10/17

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Projectiles launched at angle ws-currently, the only angles I can cover (this applies to free response-I can still cover concepts) are 0 degrees, 180 degrees, 90 degrees (straight up), and straight down.

Lab-projectiles lab-finding the angle to get max range

10/17

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Projectile simulation lab

Projectiles-3 questions

10/18

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Projectiles-questions and concepts

Projectile  lab-horizontal shot

Quiz next class

10/19

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Quiz-projectiles

Test –Oct. 24

10/20

Review questions

Begin forces notes

Test-Free response next class

Test –Oct. 24

10/21

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Kahoot review

Test next class

Review due next class

Oct. 24

Goal: the student will be able to add vectors in one dimension and vectors that are at right angles to each other.

Goal:  The student will be able to solve for a, v, t, and d.  The student will understand that the downward force of gravity has no effect on horizontal motion.

Test-2D motion, vectors and projectiles

10/29

10/25

Goal:  the student will understand the relationship between Force and acceleration and mass and acceleration.

Goal: the student will be able to solve for various forces, and acceleration.

Begin forces notes

Notes-forces

• Forces

Force- a push or pull

Gravitational force- force between all objects.  Any mass exerts a force upon any other mass

Electromagnetic force- forces between charged particles.

Strong Nuclear force- holds particles in nucleus of an atom together. (strongest)

Weak force- a form of electromagnetic force from radioactive decay.

• Newton’s 1st Law of Motion

Otherwise known as Newton’s Law of Inertia

States:  an object with no force acting on it remains at rest or moves with constant velocity in a straight line.

Inertia:  the tendency of an object to resist a change in its state of motion.  Inertia is dependent upon mass.

• Newton’s 1st Law
• In other words,
• Newton’s 1st law: an object at rest will stay at rest and an object in motion will stay in motion at a constant velocity in a straight line unless acted upon by an outside force.
• Newton’s 2nd Law of Motion

Force = Mass x Acceleration

Units: Newton’s

Newton =  kg m/s^2

Newton’s 2nd law is also known as the law of acceleration

• Newton’s 2nd law

Problem:

What net force is required to accelerate a 1500 kg race car at 3 m/s2?

• Newton’s 3rd Law of Motion

When one object exerts a force on a second object, the second exerts a force on the first that is equal in magnitude but opposite in direction.  For every action there is an opposite and equal reaction.

Action-Reaction

• Mass and Weight

Weight is the gravitational force exerted by the earth.

Weight = Mass x Acceleration due to Gravity

Ex.  Find the weight of a 2.3 kg bag of sugar.

• Friction

The force that opposes motion between two surfaces that are in contact.

Static Friction – the force that opposes the start of motion.  Ex. Pushing a box

Sliding Friction – the force between surfaces in relative motion.  Sliding friction is also called kinetic friction.  Ex. Pushing a box

• Net Forces

The net force is the vector sum of all forces acting on a body.

The acceleration of an object is always in the same direction as the net force.

Air resistance to falling objects is called drag.

Terminal velocity – when the drag force equals the force of gravity.  Do you know the terminal velocity for the average person?

• Questions
• Question #2-3
• Caitlin, mass = 58 kg, is going sky diving. Air resistance provides a lift of 60 N.  Find the net force acting on her and her acceleration.
• A 2 kg object has an acceleration of 10 m/(ss) to the right. A force of 5 N acts on it towards the left.  Find the net force acting on the object and what force must be acting towards the right.
• Friction Continued

Coefficient of Friction – a constant that depends upon the 2 surfaces in contact.

The higher the coefficient of friction, the greater the frictional force will be between the two surfaces

Equation:                             Ff = µ Fn

Force of Friction = Coefficient of Friction x

Normal force (perpendicular force)

• Problem Solving
1. Sketch the drawing
2. Draw the arrows representing the forces
3. Label each arrow with the force it is representing.  Be Specific!
• Example Problems

Ex.  Elevator

Fnet =  Fapplied +  Wt.

Net force is equal to the sum of the applied force + the weight.

Example:   A spring scale hangs from the ceiling of an elevator. It supports a package that weighs 25 N.  A) what is the upward force the scale exerts when the elevator is not moving?  B) what force must the scale exert to accelerate the package 1.5 m/s2?

Oct. 26

Goal:  the student will understand the relationship between Force and acceleration and mass and acceleration.

Goal: the student will be able to solve for various forces, and acceleration.

Finish Forces notes

Friction Notes:

## Friction Notes

____________________ is the force that tends to __________________ the motion between two surfaces in contact.  It acts __________________ to the direction of motion.

Static friction (Fs) is the force that _________________ the start of motion.  As long as the object does not move, the static friction is _____________ to and opposite to the force applied.  For example, David pushes a M1 Abrams tank with a force of 900 N.  The tank remains stationary.  The force of static friction acting against the object’s motion is _____________________.  In other words, Fs = - Fapplied or –Fs = Fapplied .

Examples:  Find Fs for the following stationary objects:

Eventually, the applied force on the object will exceed Fs max (the max static friction) and the object will _________________.  When solving any problems, we will assume that Fs max = Fapplied (or that the maximum static friction is equal to the force applied).

The force between surfaces in relative motion is called ___________________ friction.  Sliding friction is also known as kinetic friction (Fk).  Sliding friction _______________ the motion of two contacting surfaces that are moving past one another.  The force of sliding friction between two objects is less than the force of static friction between two objects.  For example, you try to push a very large and heavy box across the room.  It will take (more or less) effort to get it to move, but once you get it moving it is (easier or harder) to keep it moving.

The normal force (Fn):  A force exerted by one object on another object in a direction that is perpendicular to the surface of contact.  The normal force is equal and opposite to the component of an object’s ____________ that is perpendicular to the contact surface.

Examples.  Find Fn :

Through experimentation, it has been found that the force of friction (Ff) depends primarily upon the ___________________ force and the types of surfaces in contact.

The force of friction can be solved using the following equation:

Where Ff is the _________________________

Fn is the ____________________________

And m is the coefficient of friction.

Example problems:

A force of 30 N is required to just move a stationary 1 kg crate.  What is the normal force?  What is the coefficient of friction between the crate and the floor?

Sara attaches a spring scale to a 1 kg book and pulls it across the floor with a constant velocity.  The spring scale has a reading of 10 N.  What is the normal force?  What is the coefficient of friction between the book and the floor?

Oct. 27

Goal:  the student will understand the relationship between Force and acceleration and mass and acceleration.

Goal: the student will be able to solve for various forces, and acceleration.

Finish friction notes

Ex. Credit project info:

1. Extra assignmnentNewton's Laws T-Shirt -
Due November8-16  except for November 14,16 test days.  Extra Test Grade -  You must decorate a T-shirt so that it illustrates one of Newton's Three Laws of Motion.  The T-Shirt must contain one of the three laws, it's definition, a picture or illustration of the law and your name.  The T-shirt must be done neatly and should cover most of it(Front and Back).  You must wear the T-shirt on all day when you present the T-shirt in front of the class.  You may work in groups of 3 but each member of your group will need to cover a different law -- you need one t-shirt per group member -- (students in groups need to be in the same class period).  Points possible will be out of 30 points.  Those T-shirts that go above and beyond the minimum standards can earn more than 30 points with a maximum grade of up to 33 points. Staples, paper and tape are not permitted on T-Shirts.  Also, please do not write with pen or pencil.  T-shirts that contain Staples, Tape, Paper, and are written in Pen or Pencil will not be graded.  YOUR NAME MUST BE ON YOUR SHIRT.

Spring Scale challenge

Ff ws-

Oct. 28

Goal:  the student will understand the relationship between Force and acceleration and mass and acceleration.

Goal: the student will be able to solve for various forces, and acceleration.

Notes-Convert your weight in LBS to N.  Given:  2.21 LBS = 1 kg

Friction lab-students will determine the coefficient of friction between their physics book and various surfaces.

1. Extra assignmnentNewton's Laws T-Shirt -
Due November 15  except test days.  Extra Test Grade -  You must decorate a T-shirt so that it illustrates one of Newton's Three Laws of Motion.  The T-Shirt must contain one of the three laws, it's definition, a picture or illustration of the law and your name.  The T-shirt must be done neatly and should cover most of it(Front and Back).  You must wear the T-shirt on all day when you present the T-shirt in front of the class.  You may work in groups of 3 but each member of your group will need to cover a different law -- you need one t-shirt per group member -- (students in groups need to be in the same class period).  Points possible will be out of 30 points.  Those T-shirts that go above and beyond the minimum standards can earn more than 30 points with a maximum grade of up to 33 points. Staples, paper and tape are not permitted on T-Shirts.  Also, please do not write with pen or pencil.  T-shirts that contain Staples, Tape, Paper, and are written in Pen or Pencil will not be graded. YOUR NAME MUST BE ON YOUR SHIRT.

Oct. 28

Goal:  the student will understand the relationship between Force and acceleration and mass and acceleration.

Goal: the student will be able to solve for various forces, and acceleration.

Net force notes-example problems

Net force ws

11/10

Net force example problems

Work on net force ws

11/11

Lab-Newton’s 3 Laws lab-students will construct balloon rockets and race them across the room.  Students will make at least one observation of each of Newton’s 3 laws.

Shirt project due on Dec. 1

*CD 4-1

*Newton’s laws review

11/12

Newton’s laws review

1. Extra assignmnentNewton's Laws T-Shirt -
Due November 15 except for.  Extra Test Grade -  You must decorate a T-shirt so that it illustrates one of Newton's Three Laws of Motion.  The T-Shirt must contain one of the three laws, it's definition, a picture or illustration of the law and your name.  The T-shirt must be done neatly and should cover most of it(Front and Back).  You must wear the T-shirt on all day when you present the T-shirt in front of the class.  You may work in groups of 3 but each member of your group will need to cover a different law -- you need one t-shirt per group member -- (students in groups need to be in the same class period).  Points possible will be out of 30 points.  Those T-shirts that go above and beyond the minimum standards can earn more than 30 points with a maximum grade of up to 33 points. Staples, paper and tape are not permitted on T-Shirts.  Also, please do not write with pen or pencil.  T-shirts that contain Staples, Tape, Paper, and are written in Pen or Pencil will not be graded. YOUR NAME MUST BE ON YOUR SHIRT.

11/13

Review-kahoots?

Work on review

11/14

Turn in review and all late forces assignments

Test-froces workout problems and

concepts  on Nov. 18

11/17

Notes-Uniform circular motion

Assignment-uniform circular motion intro ws

Review for forces test

11/18

Forces concepts test

Turn in review ws

11/19

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Finish notes on uniform circular motion

• Uniform Circular Motion
• An object going in a circle at a constant speed.
• Question: is an object that is undergoing uniform circular motion accelerating?
• rotation
• rotation: when an object spins or rotates around an internal axis.  Example:  A krispy kreme rotating around a straw.
• Revolution
• revolution: when an object turns or revolves around an external axis.  Example:  A planet revolving around a star.
• Linear speed and tangential speed
• linear speed: distance moved per unit of time (speed).
• tangential speed (Vt) : the speed of an object that is moving along a circular path.  The direction of motion is tangent to the circle.
• Angular speed, force, period
• angular speed (w): the number of rotations per unit of time. Also called rotational speed.
• centripetal force (Fc): any force that will cause an object to take a circular path.
• period: the time for one revolution
• Frequency and period
• Frequency: number of revolutions (turns) per time unit (usually seconds).
• Frequency: number of events/time
• The frequency and period are reciprocals of each other
• Key Points for Uniform Circular Motion
• All points on a rotating rigid object will have the same angular speed (and thus the same angular acceleration).
• The tangential speed of an object placed on a rotating body will increase as it is moved away from the center of the rigid body.
• An object that is following a circular path has a net force (Fc) and acceleration (ac) that are acting towards the center of the object.
• Key points continued
• Velocity is always tangent to the circle and is always changing.
• Acceleration goes
• towards the center of
• the circle
• Look at the following rotating disk. Which point has the greater tangential velocity?  Which point has the greater angular velocity?
• Formulas
• Equations:
• ac = vt2                                 Fc = mac = mvt2
•   r                                                                            r
• vt = rw ß  w must be in radians per time unit
• Ac = rw2
• Reminders:
• 1 revolution = 360 degrees = 2 p rad
• for one revolution v = d =    2 p r
• t                 T

11/20

Review Force of friction and normal force

Shirt project presentations

11/21

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Assignment-circular motion ws I

Notes-Uniform circular motion

examples

12/1

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Notes-circular motion example problems:

Circular motion Example Problems

1. A queen Pogonomyrmex, m = 100 g, is flying around a 50 cm circular path. She experiences a force of 2 N acting towards the center of the flight path.  Find the ant’s tangential speed.
2. An F-22 raptor, m = 19, 700 kg, is flying at 400 m/s in a circular path with a radius of 1 km. Find the centripetal force acting on the raptor.
3. A great white shark circles a prey item with a leisurely speed of 4 m/s. The large shark has a centripetal acceleration of 0.5 m/s2.  The shark has a mass of 1000 kg.  Find radius of motion.
4. A 500 g bird makes two complete revolutions in 4 seconds with a diameter of 110 cm.
5. find the period
6. Find the frequency of motion
7. The tangential speed in cm/sec and m/sec
8. The centripetal acceleration in cm/sec2 and m/sec2
9. The centripetal force acting on the bird

Look at the following doughnut.  Assume that the tasty pastry is rotating at a constant rate.  The three dots represent ants that are riding the doughnut like a merry-go-round.

1. Which ant will have the greatest tangential speed? Explain.
2. Which ant will have the greatest linear speed? Explain.
3. Which ant will have the greatest centripetal force? Explain.
4. If the force of friction was no longer great enough to hold ant C on the doughnut, how would it fly off?

Go over a couple of problems from the circular motion I ws

12/2

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Warm up on board-complete on your own paper

Warm up àAn object is placed 5 m from the center of a rotating disk.  The object has a tangential speed of 10 m/s.  A force of 20 N is required to keep the object going in a circle.   Find:  a) radius b)  diameter c) linear speed d) centripetal force   e) mass of the object

Review the following terms:

Period

Frequency

Tangential speed

Centripetal acceleration

Centripetal force

Centripetal force vs centrifugal force

Critical velocity

Circular motion bird ws

Test on Dec. 10

12/3

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Warm up:  on board

12/4

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Circular motion lab

12/5

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Warm up:

Uniform circular motion-warm up

A hollow toy airbus 380 is attached to the ceiling with string.  An ant is riding in the pilot’s seat.  The plane is traveling in a circle that has a diameter of 200 cm.  The air bus makes 20 revolutions in 40 seconds.  The toy plane has a mass of 100 g.

What is the frequency of the plane?

What is the period of the plane?

What is the linear speed of the plane (in m/s)?

What is the acceleration of the plane (in m/s2)?

What is the centripetal force?

What is the direction of the centripetal force acting on the plane?

What is the direction of the centripetal acceleration?

What object provides the centripetal force to the plane?

What provides the centripetal force to the ant?

If the string breaks, how will the plane fly off?

Circular motion II ws

Quiz on Dec. 9

Test on Dec. 10

12/8

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Warm up:

Warm up-circular motion

A toy 200 g bird is attached to the ceiling with a string.  With a gentle push and turning on the “on” button, the bird flies in a circle that has a radius of 100 cm.  The bird completes 10 revolutions in 30 seconds.

Find the frequency of the toy bird in Hz

Find the period of the toy bird in sec.

Solve for the linear speed of the bird in m/s

Step 1:  convert the bird’s flight radius into meters.  100 cm = _________ m.

Step 2:  realize that I do not have enough information to use the following formulas with linear speed:    F =(mv2)/r                                a = v2/r

Step 3:  Understand that I have the period (T) and the radius (r) of the bird and with that I can use

v = ______________.   Since you are solving for the velocity in m/s, the radius should be in _________.

Step 4.  Solve for the linear speed.

Solve for the acceleration of the bird in m/s.

Step 1:  Determine which formula you should use.  You have the radius (r) of the bird and the linear speed of the bird (v).  You want to solve for the acceleration (a).  The formula that you must use has all three of these variables (a, v, r).

Step 2:  write down the formula.  The formula that you are using is a = _________________.

Step 3:  solve for a.  Make sure that your radius is in m and your velocity is in m/s.

Find the centripetal force acting on the bird in Newtons.

Step 1:  convert the mass in grams to kg.  200 g = _____________ kg.

Step 2:  Choose your formula.  You must pick a formula that has force in it.  Some wise choices:

F = ma                   or           F = (mv2)/r

Make sure that your mass is in __________ and your radius is in __________.

Step 3.  Solve for the force.

A humming bird’s wings have a frequency of 200 Hz.  Find the period.

Matt spins a 100 g ball in a circle with a radius of 50 cm.  Find the critical velocity that he needs to spin it with.

Kim and Kelsey sit 2 m from the center of a merry-go-round.  They have a centripetal acceleration of 8 m/s2.  Find their linear speed.

Review ws

Finish circular motion II ws

Quiz next class

Test Dec. 10 and quiz Dec. 9

12/9

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Circular motion quiz -notes are allowed?

Test Dec. 10

Review due on test day

12/10

Goal:  students will be able to solve for velocity, centripetal force, centripetal acceleration.

Goal:  students will understand that centripetal acceleration and force are directed inward towards the center of the object’s circular motion.

Circular motion test today

Review due today

12/11

Notes-Newton’s Laws of Universal Gravitation

• Universal Gravitation and Kepler’s Laws
• Keplers 1st Law of Planetary Motion
1. The paths of the planets are ellipses with the center of the sun at one focus.
• Kepler’s 2ndLaw of planetary motion
1. An imaginary line from the sun to a planet sweeps out equal areas in equal time intervals.  Thus, planets move fastest when closest to the sun, and slowest farthest from the sun.

.

• Kepler’s Third Law
• The ratio squares of the periods of any two planets revolving around the sun is equal to the ratio of the cubes of their average distances from the sun
• Kepler’s Laws cont’d

Equation:  (Ta/Tb)2 = (ra/rb)3

Planet A’s period divided by planet B’s period squared = average distance of A divided by the average distance of B cubed.

Ex.  Galileo discovered 4 moons on Jupiter.  Io which he measured to be 4.2 units from the center of Jupiter has a period of 1.8 days.  He measured the radius of Ganymede’s orbit as 10.7 units.  Use Kepler’s 3rd Law to find the period of Ganymede.

• Newton’s Law of Universal Gravitation

The gravitational force between any 2 bodies varies directly as the product of their masses and inversely as the square of the distance between them.  Also called the inverse square law.

Equation:  F= G m1m2/d2

Force equals Universal constant x mass of body 1 x mass of body 2 / distance squared

• Example Problem UG
• A 2 kg mass is at rest on the surface of the Earth. Find the force of attraction that exists between the mass and Earth.  The radius of Earth is 6.4 x 10^6 m.  The mass of earth is 6 x 10^24 kg.
• Motion of Planets and Satellites

To solve for the velocity of a satellite the equation is :     v = (square root of) Gme/r

The time for the satellite to orbit the earth is the period or T.

Equation:             T = 2P (square root of ) r3/Gme

Acceleration of gravity Calculated:

a= g(Re/d)2

• Universal Gravitation Example Problems
• What happens to the force of attraction if one mass is doubled?
• What happens to the force of attraction if the distance between the two objects is doubled?
• What happens to the force of attraction if both masses are doubled and the distance is tripled?
• Q
• Questions
• What force holds the planets in orbit around the sun?
• What would happen to the planets if this force was insufficient, or the velocities of planets increased greatly?

UG ws

Quiz on Monday?

Project info-due Friday-highly tentative

On your semester exam you may use one 3x5 note card.  Hand written on the front and the back.

12/12

Example problems/warm up

Universal Gravitation Example Problems and Warm  up

Givens:  mE = 6 x 1024 kg                         rE = 6.4 x 106 m                       mmars = 6.4 x 1023 kg

Distance between Earth and Mars = 8 x 1010 m

Example problems.

1. The force of attraction between a small cat and the planet Earth is 49 N.  Find the mass of the cat (it is safe to assume that the cat is in Earth)
2. What would happen to your weight if:
1. Your mass doubled
2. The radius of Earth increased 5 times
3. The mass of the Earth doubled and you the radius of earth increased 4 times

Warm up

1. Find the force of gravity between a gigantic 2 kg hamburger and the Earth.

1. The force of attraction between the Earth and a 1000 kg orbiting satellite is 10 N.  Find the distance between the Earth and the satellite.

1. What would happen to the force of attraction between two objects if
1. One mass is doubled and one mass is tripled
2. One mass is increased 4 times and the distance between them is doubled

Finish UG WS and turn in

Work on the project!

Quiz on Thursday or Monday (probably Thursday)

12/15-12-19

Review ws for the semester exam-you may use one 3x5 note card on the semester exam.  Hand written!

Work on review and make your 3x5 note card

Semester Exams!

Test-Sept. 8-math review