
Jan. 5
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Impulse momentum notes
 Momentum
 Internal and External Forces
Internal Force – the forces between objects in a system.
External Forces – forces exerted from outside a system.
 It is important to define a system carefully to determine the status of the force.
 Inertia
 Recall that inertia is the tendency of an object to resist a change in its motion.
 Inertia is based upon mass
 Momentum and Impulse
 Momentum is a vector. The product of mass and velocity is momentum.
 Momentum is a quantity that is in the same direction as velocity.
Equation: p = m v Unit: kg*m/s
Momentum = mass * velocity
Momentum can be thought of as inertia in motion.
 Example
 A truck (m = 1700 kg) has a velocity of 4 m/s. A compact car (m = 900 kg) has a velocity of 10 m/s. Find the momentum of each.
 Impulse
The product of the net force and the time interval over which it acts.
Impulse is a vector quantity in the direction of the Force.
Equation: Impulse = F êt Units: Newtonseconds
Example: Car Crash
 ImpulseMomentum Theory
The equality of impulse and change in momentum is another way of writing Newton’s 2^{nd} Law.
Equation: Fêt = êp
Force * change in time = change in momentum
 Example question
 A 500 g ball starts with a velocity of 10 m/s E. A bat hits the ball and is in contact with the ball for 0.1 sec. After being hit, the ball has a velocity of 10 m/s W. Find:
 The balls impulse
 Its change in momentum
 And the force the bat applied to the ball
 Angular Momentum
The product of an object’s mass, velocity, and distance from the center of rotation.
Ex. Hurricane’s have a large Angular momentum
 Conservation of Momentum
Law of Conservation of Momentum states that The Momentum of any isolated, closed system does not change.
The total momentum of an isolated system always remains constant.
The impulsemomentum theorem is another way of stating Newton’s 2nd law
 Conservation of Momentum
Equation: p_{a }+ p_{b }= p_{a}’ + p_{b}’
The momentum of 2 objects is equal to the momentum after a collision.
 Conservation of momentum Example problems
 A large box car (m = 2000 kg) heads east with a velocity of 2 m/s. It collides with a smaller box car (m=1500kg) at rest. The two box cars combine at impact. Find their velocity after impact.
 An object of mass M heads towards the E with a velocity of 4 m/s. An object of mass 4 M heads W with a velocity of 12 m/s. The two collide and combine at impact. Find their velocity after impact.
 Conservation of Momentum in 2 Dimensions
The total momentum of a system is the vector sum of the momenta of all parts of the system.
Example. Pool balls colliding at an angle and the direction they will go in.
 Find the impulse and the force acting on the egg.
 #1 You throw a 100 g egg at a fire blanket with a velocity of 10 m/s. It hits the blanket and comes to a complete stop in 0.8 seconds.
 #2 You throw a 100 g egg at a wall with a velocity of 10 m/s. It hits the wall and comes to a complete stop in 0.1 seconds.
 #3 compare and contrast your results.
Momentum ws
Impulse momentum testJan. 30?
Jan. 6
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Impulse momentum example problems
Impulse momentum ws
Impulse momentum testJan. 28
Impulse momentum review ws
Jan. 9
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Students will understand that momentum is conserved (law of conservation of momentum)
Conservation of momentum example problems
 A 1500 kg car traveling west at 30 m/s hits a 4500 kg truck traveling east with a velocity of 20 m/s. What is the velocity of the combined vehicles after impact?
 A 3 kg ball with a velocity of 4 m/s and a 1 kg ball with a velocity of 2 m/s are thrown directly at each other. The balls collide and merge at impact. What is the velocity of the merged ball after impact?
 A 50 kg projectile leaves a 240 kg launcher with a velocity of 350 m/s. What is the velocity of the launcher after the projectile has been fired?
The following are perfectly elastic collisions or are not perfectly inelastic collisions.
 A 2 kg ball traveling west at 5 m/s collides headon with a 1.60 kg ball traveling west at 9 m/s. After the collision, the 2 kg ball moves back with a velocity of 8 m/s (towards the east). Find the velocity of the 1.6 kg ball after the collision.
 A 25 g marble moving towards the right with a velocity of 20 cm/s collides with a 10 g marble that is moving towards the right at 15 cm/s. After the collision, the 10 g marble moves to the right with a velocity of 22.1 cm/s. Find the velocity of the 25 g marble after the collision (answer in cm/s).
 A 16 kg object moving towards the left (v = 12 m/s) hits a 4 kg object moving towards the right with a velocity of 6 m/s. After the collision, the 4 kg object has a velocity of 22.7 m/s towards the left. Find the velocity of the 16 kg object after the collision.
Conservation of momentum ws
Jan. 10
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Students will understand that momentum is conserved (law of conservation of momentum)
Review impulse momentum
Work on review ws
Impulse momentum test
Jan. 20
Jan. 11
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Students will understand that momentum is conserved (law of conservation of momentum)
Impulse momentum testJan. 20
Conservation of momentum wsuse as study guide for the quiz
Jan. 12
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Students will understand that momentum is conserved (law of conservation of momentum)
Impulse momentum waterballoon lab
Review ws
Jan. 13
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Students will understand that momentum is conserved (law of conservation of momentum)
CD 71important concepts
Jan. 17
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Students will understand that momentum is conserved (law of conservation of momentum)
Labimpulse momentum egg safety lab
Jan. 18
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Students will understand that momentum is conserved (law of conservation of momentum)
Collisions ws
Jan. 19
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Students will understand that momentum is conserved (law of conservation of momentum)
Impulse momentum kahoot
Jan. 20
Goal: students will be able to solve for F, t, impulse, p, v. Students will understand that seat belts and air bags help protect people by extending the time (and decreasing the force) if an accident occurs.
Students will understand that momentum is conserved (law of conservation of momentum)
Impulse momentum test
Jan. 23
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Begin work, power, energy notes
5A: interpret evidence work energy theorem 5B: observe and describe examples of kinetic and potential energy and their transformations.
Students will be able to calculate kinetic and potential energy. 2. Equations: 3. Energy notes:
 Energy Forms
Kinetic Energy – energy that has motion
Potential Energy – stored energy because of its state or position.
 kinetic energy depends upon an object’s mass and velocity.
 Doing work on an object can increase the kinetic energy.
Formula: KE= ½ m v^{2 } Unit: joules
 Energy Forms
 Mechanical Energy: The total kinetic and potential energy for an object (or multiple objects)
 Example
 What is the kinetic energy of a 1kg block that is moving with a velocity of 2 m/s?
 Work, Energy Theorem
The work energy theorem states that the change in the kinetic energy of an object is equal to the net work done in it.
Net Work = ½ mvf^2 – ½ mvi^2
 Potential Energy
GPE = Gravitational Potential Energy
Energy that depends upon the objects position above the earth’s surface.
Equation: GPE = mgh
GPE = mass * acc due to gravity* height
Units: joules
 Example
 What is the gravitational potential energy of a 2 kg object that is raised to height of 10 m?
 GPE = mgh
 GPE = 2(9.8)(10)
 GPE = 196 J
 Conservation of Energy
Law of Conservation of Energy:
Within a closed, isolated system, energy can change form, but the total amount of energy is constant. Energy can not be created or destroyed. Ex. Kinetic to Potential Energy
 Questions about Energy
 1. An object is being lifted up. Is the object’s GPE increasing or decreasing?
 2. A rock is falling down. As it is falling down, what is happening to its GPE? As it is falling down, what is happening to its KE?
 3. What happens to the KE of an object when: a) mass is doubled b) velocity is doubled c) velocity is halved
 Conservation of Mechanical Energy
 Mechanical energy is always conserved in a closed system (no friction)
 a decrease in potential energy is accompanied by an increase in kinetic energy.
Formula: KE_{i }+ PE_{i} = KE_{f} + PE_{f }
 Problem
A large chunk of ice with a mass of 15 kg falls from a roof 8m above the ground. Find the KE of the ice when it reaches the ground. What is the speed of the ice when it reaches the ground?
KE + PE (initial) = KE + PE (final)
knight912@gmail.com } Energy  the ability to do work  The SI unit for energy is the joule (J) (a scalar quanitity) } Potential Energy  Energy of position or stored  An object gains gravitation potential energy when it is lifted from one level to a higher level. Therefore, gravitation potential energy is directly proportional to the objects height. PE=U=m*g*h } Kinetic Energy  Energy of motion  The kinetic energy varies with the square of the objects speed. KE=1/2(mv^2) } The Law of Conservation of Energy  states that energy is not created or destoryed. The total amount of mechanical energy remains constant if no work is done by any force other than gravity.
Energy
The work energy theorem states that the change in the kinetic energy of an object is equal to the net work done in it.
Net Work = ½ mvf^2 – ½ mvi^2
 Potential Energy
GPE = Gravitational Potential Energy
Energy that depends upon the objects position above the earth’s surface.
Equation: GPE = mgh
GPE = mass * acc due to gravity* height
Units: joules
 Example
 What is the gravitational potential energy of a 2 kg object that is raised to height of 10 m?
 GPE = mgh
 GPE = 2(9.8)(10)
 GPE = 196 J
 Conservation of Energy
Law of Conservation of Energy:
Within a closed, isolated system, energy can change form, but the total amount of energy is constant. Energy can not be created or destroyed. Ex. Kinetic to Potential Energy
 Questions about Energy
 1. An object is being lifted up. Is the object’s GPE increasing or decreasing?
 2. A rock is falling down. As it is falling down, what is happening to its GPE? As it is falling down, what is happening to its KE?
 3. What happens to the KE of an object when: a) mass is doubled b) velocity is doubled c) velocity is halved
 Conservation of Mechanical Energy
NotesReview Kinetic and PE.
Emphasis on conservation of energy.
} Mechanicl energy  The total kinetic and potential energy of an object (or objects) } The work energy theorem states that the change in the kinetic energy of an object is equal to the net work done on it. } Mechanical energy is always conserved in a closed system (no friction). This means that a decrease in the GPE is acompanied by an increase in the KE } the GPE lost = the KE gained 5. Energy questions: a) An object is being lifted up. Is the GPE increasing or decreasing? b) A rock is falling down. As it is falling, what happens to its GPE? (the KE) c. A large chuck of ice with a mass of 15 kg fall from a roof 8 m above the ground. Find the KE of the ice when it reaches the ground and its speed.
Jan. 23
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Kinetic energy assignment
Work, power, energy packet
Jan. 24
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Energy work power warm up packetmake sure you do a few problems a day until the testfirst three questions
Conservation of energy assignment
Jan. 25
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Energy work power warm up packet
Conservation of energy ws II
Jan 26
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Start CPO energy Labroller coaster labStudents will determine the KE and PE of a steel marble at various points. This lab will take several periods to complete
Jan. 27
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Finish lab (CPO energy Lab)
Jan. 30
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Warm up packetconservation of energy problems
Work, power notes
Energy ws > Kinetic and potential energy
 Energy
 Energy is sometimes defined as the ability to do work.
 Energy is a scalar
 Work is a scalar
 Work
Work the product of the force exerted on an object and the distance the object is moved in the direction of the force.
Ex. Carrying an object
Formula: Work = Force x distance
Units: Joules
Also: Work = Force x distance x cosq
*when there is an angle of force.
 Work
 Work is done on any object when a force is applied to it and it moves (has a displacement). If the force applied and the displacement of the object are perpendicular to each other, NO work is done on the object.
 The WorkKinetic Energy Theorem
 The net work done on an object is equal to the object’s change in kinetic energy.
 Formula Wnet = DKE or W = KEf – Kei
 Example
 Due to friction, a sliding sled’s kinetic energy drops from 300 J to 50 J. What work (net) is done on the sled?
 Wnet = KEf – KEi
 Wnet = 50 – 300
 Wnet = 250 J
 What does the negative sign mean?
 Work Continued
 A negative sign on work means that the work done on the object caused it to slow down, or was directed against an object’s motion.
 Power
Power the rate at which energy is transferred.
Formula: Power = Work/time
Units: Watts
 Power
 The higher the power output, the more quickly work is done
 Brain food: one hp = 750 Watts
Assignmentwork I
Jan. 31
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Assignmentpower I
Feb. 1
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Power labstudents will determine their own power output
Work power energy test coming soon (next week)
Review ws
Feb. 2
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Work II
Feb. 3
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Testwork power and energy coming soon
W,P,E assignment
Feb. 6
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Work power energy kahoot
Feb. 7
Goal: be able to solve for W, P, t, F, d, KE, and PE
Goal: understand that energy is conserved although it can change forms
Goal: understand that work occurs when a force is applied to an object and it moves (not at right angles to each other)
Work power energy test
Feb. 8
Goal: be able to solve for f, T, v, fd
Goal: understand that waves transfer energy
Goal: understand the Doppler effect
Waves notesending with a waves video
Waves
A wave transfers energy from place to place without transferring matter
Waves travel through a medium (a substance). All waves need a medium except electromagnetic waves, which can travel through a vacuum.
Transverse Waves
Wave where the medium moves at right angles to the wave.
Parts of a Transverse Wave
Crest  highest point of wave
Trough  lowest point of wave
Wavelength  distance between one point in a wave and the exact point on the next wave. Ex. Crest to Crest
Amplitude  distance from crest to middle
Compresional Waves
Compression Waves are waves that the media and waves vibrate in the same direction. Otherwise known as longitudinal waves Ex. Sound
Compression Waves
Compression  compact area of wave
Rarefaction  less dense area of Compression Wave
A Wavelength of 1 Compression Wave consists of 1 Compression and 1 Rarefaction
Wave Frequency and Velocity
Frequency (Hz)  the number of wavelengths in one second, expressed in a unit called Hertz( 1 wavelength per 1 second) Frequency = 1/ period
Period (s) = 1 / frequency or the time of one wavelength.
Velocity (m/s) = Wavelength x Frequency
V= f x l(lambda) symbol for wavelength (measured in meters)
Example Problems
A mosquito beats its wings 200 times in 2 seconds. Find its frequency and period
An object vibrates back and forth 4 times in four seconds and produces waves. Each crest has an amplitude of 2 m and the crests are separated by 3 m. Find the velocity of the wave.
Interference
Constructive Interferencewhen waves meet crest to crest or trough to trough, an additive effect.
Destructive Interference when the crest of one wave fills in the trough of another wave, a canceling effect.
Interference Examples
Two different waves interfere with each other. One wave has an amplitude of 3 m, the other 2 m.
What is the resulting amplitude if the two waves meet in phase (crest to crest)?
What is the resulting amplitude if the two waves meet out of phase (crest to trough)?
Standing Waves
Standing Wave – wave where certain parts of the wave remain stationary due to interference.
Nodes stationary parts of a standing wave
Antinodes positions on a standing wave with the largest amplitudes. They occur halfway between the nodes.
Harmonics
A type of standing wave produced when destructive interference produces a point with no movement and constructive interference produces a point with maximum displacement.
Harmonics
1^{st} harmonic 2^{nd} harmonic 3^{rd} harmonic
Doppler Effect
Doppler Effect change in frequency due to the motion of the source or observer. Named after the Austrian scientist Christian Doppler.
 The greater the speed of the source (or observer) the greater the Doppler Effect.Doppler EffectFrequency detected = frequency of source x (velocity of wave + velocity of detector) / (velocity of wave  velocity of source)Where:vd is negative if the detector is moving away from the sourcevs is negative if the source is moving away from the detectorA mosquito is flying towards you with a velocity 10 m/s while beating its wings with a frequency of 500 Hz. You are moving away from the mosquito with a velocity of 2 m/s. What frequency of sound do you hear? Goal: be able to solve for f, T, v, fdGoal: understand the Doppler effect What is SoundSound is a longitudinal wave (compression wave)Pitch  highness or lowness of sound due to frequency of sound, high frequency  high pitch low frequency  low pitch. Low Pitch – fog hornBeatsEx. A 200 Hz sound and a 203 Hz sound will produce a beat frequency of . . . Labmusical toneinvestigating frequency and wavelength Feb. 10Goal: understand that waves transfer energy Rubber 60m/s Air (0 deg C) 331Water (25deg C) 1498 m/sWood 3850 Glass 4540Stone 5971Humans have 3 parts to their ears. Outer, Middle, and Inner Ears.Middle intensifies the vibrations with 3 bonesMusicNoise  No Pattern or Pitch.Music Cont’dOvertones have frequencies that are multiples of original frequencies Ex. Musical NotesMusic Cont’dBow Waves and Shock WavesShock wave similar to a bow wave, but a shock wave is produced by overlapping spheres that form a cone. Ex. Super sonic jet. ResonanceNatural Frequency – frequency of vibrations of elastic objects that create their own special sound. Ex. Bells and Tuning forksIntensity and Loudnessloudness is the human perception of sound intensityJet 150, Chain Saw 115, Mower 100, Restaurant 80, Vacuum 75, Whisper 20 Reflection: when a wave strikes a barrier and bounces off
 Refraction: when a wave goes from one medium to another and bends due to a change in speed
 Reflection and Rarefaction
 Loudness in decibels of various objects
 intensity depends upon the amount of energy in a wave
 Resonance – when a forced vibration matches the objects natural frequency. Ex. Swing
 Forced Vibration vibration of an object that is made to vibrate by another vibrating object that is nearby. Ex. Tuning forks
 Sonic Boom  sharp crack heard on the ground produced by a shock wave.
 Bow wave A wave in which the crests of the waves overlap the original waves. Ex bug swimming faster in water than the waves produced by the bug. Also speedboat
 Acoustics is the study of sound Ex. Good Acoustics is a Concert Hall or Auditorium.
 Interference is the ability of 2 or more waves to combine to form one.
 Sound Quality describes the differences among sounds. Ex. Violin and Piano
 Resonance  If the sound that reaches an object is at the same frequency as the natural frequency of the object, the object will begin to vibrate at this frequency. Ex. String Insturments
 Using Specific Pitches and Sound Quality by following a regular pattern.
 Inner (fluid filled) sends nerve impulses to brain to be deciphered.
 Outer directs sound to eardrum
 Human Hearing
 Iron 5103 Steel 5200
 Sea Water at 25 deg C. 1531 m/s
 Air (25deg C) 346 m/s Lead 1210
 Complete wave notes
 Goal: understand the Doppler effect
 Goal: be able to solve for f, T, v, fd
 When two sounds are close in frequency, beats may be heard. A beat is heard when you hear a loud sound followed by a faint sound.
 The human ear can hear pitches from about 20 Hz to about 20000 Hz
 High Pitch  piccolo
 Frequency and Pitch
 Sound is caused by waves that are picked up by your ears
 Continue waves notes
 Goal: understand that waves transfer energy
 Feb. 9
 Speed of Sound
 Doppler Effect example problem
 And the velocity of the source (vs) is positive if it is moving towards the detector
 the velocity of the detector (vd) is positive if it is moving towards the source
 Doppler effect formula
 Doppler Effect Formula
 Example: Fire Engine, Police radar
 Sound Waves: Practical Applications
 Industrial Uses
 High frequency sound waves (ultrasound) is sometimes used as a cleaning tool
 Echo Location
 Sound waves are used as a means of echo location.
 A sound wave is emitted from a source, bounces off obstacles and returns to a receiver
 Medical uses of sound waves
 Sonograms
 Sound waves are used to burst apart mineral deposits in the body (such as kidney or gall stones).
 Disassociation of tumors
 For the test
 Know all 3 of the bones in the middle ear! This means you must look them up!Assignmentwaves ws Feb. 13Goal: understand that waves transfer energy Waves II ws Goal: be able to solve for f, T, v, fdGoal: understand the Doppler effectSound waves labproperties of sound waves.Review wsFeb. 15Goal: understand that waves transfer energy Doppler effect ws Goal: be able to solve for f, T, v, fdGoal: understand the Doppler effectWaves notesfrom moodleWaves practice problemsFeb. 17Short activity/labTransverse waves vs compression wavesshown with a slinky Goal: be able to solve for f, T, v, fdGoal: understand the Doppler effectDoppler II ws ( a more challenging assignment) Feb. 22Goal: understand that waves transfer energy Quiz next weekprobably Wed. Goal: be able to solve for f, T, v, fdGoal: understand the Doppler effectPhysics and writingWaves testFeb. 28Quiz next classBring your notes! Goal: be able to solve for f, T, v, fdGoal: understand the Doppler effectWaves quiz Physics and writingWhat have you learned about waves?How to find frequency, velocity, period and wavelengthReview conceptsTest March 2waves Goal: be able to solve for f, T, v, fdGoal: understand the Doppler effect Reviewconstructive and destructive interference, beats, harmonics, compression waves, Doppler effect, transverse waves Questions on the board to solve: Feb. 27Goal: understand that waves transfer energy Testwaves and soundconceptsfree response March 1Goal: be able to solve for f, T, v, index of refractionsNotesLight
 Goal: understand the nature of light, including reflection and refraction
 Test March 2waves conceptsMC
 Feb. 28
 Kahoot reviewwaves
 Goal: understand the Doppler effect
 Goal: be able to solve for f, T, v, fd
 A radio station is broadcasting at 99.5 MHz. Find the wavelength of the wave.
 A visible light ray has a wavelength of 700 nm. Find the frequency.
 Review waves problemsdoppler effect, v = lf, f = 1/T, T = 1/f, f = events / time
 Physics and writing assignment
 Testwaves and soundfree responseon Feb. 28
 Physics and writing assignment
 Goal: understand that waves transfer energy
 Feb. 27
 Waves III
 How to find frequency detected
 Review sound waves
 Feb. 23
 Goal: understand that waves transfer energy
 Feb. 24
 Waves review sheet
 Waves and sound ws
 Goal: understand that waves transfer energy
 Feb. 23
 Test Feb. 28
 Resonance labresonance lab using the CPO equipment
 Goal: understand the Doppler effect
 Goal: be able to solve for f, T, v, fd
 Goal: understand that waves transfer energy
 Feb. 21
 Physics project infoboat race and boat race video
 Doppler effect video
 Waves reading activityfrom moodle
 Goal: understand that waves transfer energy
 Feb. 16
 Waves testFeb. 28
 Doppler effect example problems
 Goal: understand the Doppler effect
 Goal: be able to solve for f, T, v, fd
 Students will investigate the properties of sound waves with the aid of a tunning fork
 Goal: understand that waves transfer energy
 Feb 14
 Sound wave demos
 Goal: understand the Doppler effect
 Goal: be able to solve for f, T, v, fd
 Light
 Nature of Light
 Light has a dual nature: it behaves as both a particle and a wave.
 Photons are bundles of electromagnetic energy that do not have mass
 The wave nature of light can be seen from interference patterns. EM waves are transverse waves.
 Speed of Light
 Physicist Albert Michelson determined the speed of light in the 1880s. He wanted to determine the speed of the “ether” through which light traveled.
 His experiment showed that the speed of light is about 300 000 km/s or 3.0 x 10^{8 }m/s
 The experiment is outlined in fig 27.3 in your book
 Electromagnetic waves
 An electromagnetic wave is (simplified) a self propagating wave that is part electric and part magnetic. It is caused by a moving charge.
 A more thorough definition: A magnetic field will be produced in empty space if a changing electric field is present. This changing electric field will produce a changing magnetic field which will produce a changing electric field. This process will repeat itself, and thus an electromagnetic wave can self propagate through space.
 The range of electromagnetic waves can be seen in the electromagnetic spectrum.
 Notice the small portion that is visible light
 EM wave
 EM spectrum
 EM Waves
 Radiation: the transfer of energy by EM waves
 High frequency EM waves have the greatest amount of energy
 High frequency EM waves behave like a photon and are high energy waves
 Low frequency EM waves behave more like a wave and are lower energy waves
 Visible light is the only part of the EM spectrum that humans can see
 Polarization
 The aligning of vibrations of a transverse wave. This is usually accomplished by filtering.
 Example: polarized sun glasses. Goal: understand the nature of light, including reflection and refraction Waves concepts testmultiple choicenext class March 3Goal: be able to solve for f, T, v, index of refractionsLight notes
 Goal: understand the nature of light, including reflection and refraction
 Waves review II assignment
 Review waves concepts
 Light ws
 Goal: be able to solve for f, T, v, index of refractions
 March 2
 Light Facts
 Visible Light is an electromagnetic wave that the human eye can detect.
 Different light wavelengths are seen as different colors.
 A ray is a straight line that represents the path of a light beam.
 Speed of Light (c) = 3.0 x 10^{8} m/s
 Light and MatterEx. Glass, plastic, Opaque absorb or reflect all light waves that fall on them. Ex. Brick
 Translucent – transmit light but objects are not seen clearly. Ex. Frosted glass
 Transparent objects that transmit light waves
 The visible spectrum of Light
 ColorPrimary colors – red , green , blue
 Secondary colors – yellow, cyan, and magenta
 Colors of the spectrum are associated with specific light wavelengths
 Polarization of lightEx. Sunglasses
 Polarization of light – light in which the electric fields are all in the same line.Light can be polarized because it is a transverse wave.
 ReflectionLaw of Reflection when a light ray strikes a reflecting surface, the angle of reflection is equal to the angle of incidence. Ex . Laser beamRegular Reflection when light rays are reflected in one direction. Ex. Smooth surface
 Diffuse Reflection when light rays are reflected in many directions. Ex Rough surface
 Reflection: When an electromagnetic wave (or any other type of wave) “bounces” off of a surface. All waves show reflection.
 Regular Reflection Example
 Diffuse Reflection Example
 RefractionRefraction of light bending of light due to the speed of light in different media. Ex Fish tankn_{i} sin q_{I} = n_{r} sin q_{r }( where n = the index of refraction of the mediumr = refracted (“second”)
 i = incident (“first”)
 Snell’s Law a ray of light bends in such a way that a ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant.
 Refraction: The bending of a wave as it passes from one medium to another medium. All waves refract when they enter new mediums
 Snell’s Law Example problem
 A beam of light in a vacuum tube hits a diamond barrier at an angle of 30 degrees (this is the angle of incidence). What is the angle of refraction?
 Make sure your calculator is in degree mode!
 Index of Refractions for various substances
 Indices of RefractionVacuum 1.0Water 1.33Crown glass 1.52Flint glass 1.61
 Diamond 2.42
 Quartz 1.54
 Ethanol 1.36
 Air 1.0003
 Medium n
 Index of Refraction and Speed of LightEquation: n_{substance} = c / v_{substance } v_{s }= c / n_{s}
 or
 The index of refraction is the ratio of the speed of light in a vacuum to the speed in the medium.
 Examples
 What is the speed of light in ethanol?
 Kayci aims a flashlight at a mirror that is in space. The light hits the mirror and returns in 5 seconds. How far away is the mirror?
 Refraction Examples
 Refraction Examples
 DiffractionDiffraction usually occurs when waves pass through small openings (like slits), around obstacles, or sharp edges
 Diffraction occurs with all waves
 Diffraction is the spreading of waves into a space or region behind an obstacle.
 Common conversions
 1 MHz = 10^{6 }Hz
 10^{9} nm = 1 m
 100 cm = 1 m
 1000 g = 1 kg
 1000 m = 1 km March 6Goal: be able to solve for f, T, v, index of refractionsNotes and diagrams of the following two questions about refraction:how does light bend when it goes from a less dense medium to a more dense medium (like air into water)?How does light bend when it goes from a dense medium to a medium that is not very dense? Goal: understand the nature of light, including reflection and refraction, and snell’s law Snells law ws March 8Goal: be able to solve for f, T, v, index of refractions Buoyancy lab Goal: understand the nature of light, including reflection and refraction, and snell’s law EM Waves Any object above absolute zero gives off ___________________ radiation. Infrared radiation has a wavelength slightly ______________ than visible light. Light (visible radiation) is the only part of the EM spectrum that you can ______________.Review refraction concepts: March 20Goal: be able to solve for f, T, v, index of refractionsLight wsproblems Goal: understand the nature of light, including reflection and refraction, and snell’s law Goal: know the EM spectrumLight wsconcpets Goal: understand the nature of light, including reflection and refraction, and snell’s law Goal: know the EM spectrumSnell’s laws diagramsassignmentstudents must use a protractor to find the angle of incidence. They will than use snell’s law to find the angle of refraction. A protractor is than used to measure and draw the angle of refraction. This assignment will take two class periodsMarch 23Goal: be able to solve for f, T, v, index of refractions Finish snell’s laws diagrams ws Goal: understand the nature of light, including reflection and refraction, and snell’s law Goal: know the EM spectrumHalf of a light wsMarch 27Goal: be able to solve for f, T, v, index of refractions Goal: understand the nature of light, including reflection and refraction, and snell’s law Goal: know the EM spectrumphysics: convection, conduction, radiation, refraction, and refelction March 29Goal: be able to solve for f, T, v, index of refractions Review ws due next class Goal: understand the nature of light, including reflection and refraction, and snell’s law Goal: know the EM spectrumTestwaves and lightMarch 31Goal: be able to use ray diagrams to find the proper location of an imageNoteslenses and mirrorsTest april 10?Intro NotesMirrors a. Flat mirrors are the simplest type of mirror. b. The image formed appears to be the same size as the object c. The object and image distance appears to be equal. d. Flat mirrors form virtual images Virtual image: an image formed by rays of light that appear to intersect at a point behind the mirror. Example: When you look in a mirror, it appears that your reflection is behind the surface of the mirror.A concave mirror is curved inward and converges incoming light rays.A real image can be projected on a surface. A real image is formed when rays of light actually intersect at a single point.Concave mirrors can magnify an object’s image (either smaller or larger)Convex MirrorsConvex mirror
 A convex mirror is an outwardly curved mirror that diverges incoming light rays Convex mirrors always produce virtual images. Convex mirrors provide a large field of view but produce a small image An example is your car mirror“objects may be closer than they appear.”
 Concave spherical mirrors
 Virtual images can also be seen with concave mirrors.
 Concave mirrors can focus light to produce real images.
 Concave Spherical mirrors
 Flat Mirror
 Demonstration of convex and concave mirrorsreal and virtual images
 Assignmentintro to thin lenses
 Goal: understand the characteristics of lenses and mirrors and the images they produce
 Goal: be able to solve for object distance, image distance, and magnification
 Goal: be able to solve for f, T, v, index of refractions
 March 30
 Test next March 30
 Review for the test with a kahoot review
 Goal: know the EM spectrum
 Goal: understand the nature of light, including reflection and refraction, and snell’s law
 Lightsuper fun wsthis assignment covers all of the topics for the light unit
 Goal: be able to solve for f, T, v, index of refractions
 March 28
 Light wsconcepts
 Goal: know the EM spectrum
 Goal: understand the nature of light, including reflection and refraction, and snell’s law
 Goal: be able to solve for f, T, v, index of refractions
 March 24
 TestLightMoved to march 30
 Review light concepts
 Goal: know the EM spectrum
 Goal: understand the nature of light, including reflection and refraction, and snell’s law
 Goal: be able to solve for f, T, v, index of refractions
 March 22
 TestMarch 26
 Goal: be able to solve for f, T, v, index of refractions
 March 21
 Formulas to use: v = lf and d = vt
 Goal: know the EM spectrum
 Goal: understand the nature of light, including reflection and refraction, and snell’s law
 You are stuck on an island. To survive, you must hunt fish with a ray gun (shoots light). While standing on a cliff, you notice a fish in the water. How should you aim your ray gun?
 You are stuck on an island. To survive, you must hunt fish with a spear. While standing on a cliff, you notice a fish in the water. How should you aim a spear to catch the fish?
 Radio waves have low frequencies and long wavelengths. Microwaves are radio waves with _______________ frequencies. Microwave ovens use ________________. In a microwave oven, microwaves transfer energy to an object (what you are cooking) and causes the kinetic energy of the object to increase.
 In 1905, Albert Einstein hypothesized that light was composed of tiny particles called _______________ . So is light (and other EM waves) a particle or a wave? The answer is _______________________. Light has a _________________ nature. EM waves behave as both a particle and a wave. Low frequency and long wavelength EM waves tend to behave more as a ______________. High frequency and short wavelength EM waves tend to behave more as a photon (particle). High frequency EM waves have the greatest photon energy.
 The shorter the wavelength of an EM wave, the _______________ the frequency. As the frequency of an EM wave _________________ the amount of energy carried by the wave increases. The electromagnetic spectrum arranges EM waves in order of wavelengths.
 Electrically charged particles produce_____________waves. EM waves are sometimes referred to as electromagnetic radiation. EM waves are_______________ waves. The transfer of energy by EM waves is called __________________. EM waves can travel through a ____________ at a speed of 3 x 10^{8} m/s. Thus, all EM waves will travel at the same speed in a vacuum.
 EM waves notes:
 Goal: be able to solve for f, T, v, index of refractions
 March 10
 Buoyancy notes
 March 9
 Snell’s law lab
 Goal: understand the nature of light, including reflection and refraction, and snell’s law
 Light testMarch 26?
 Goal: be able to solve for f, T, v, index of refractions
 March 7
 Index of refraction assignment
 Goal: understand the nature of light, including reflection and refraction, and snell’s law
 Thin LensesIntro Notes
 A lens forms images by refracting (bending) light while a mirror reflects light
 The Focal Point
 Light rays from an object that is very far away are nearly parallel
 The focal point of a lens is the place where the refracted light waves from a distant object converge (or appear to converge)
 The focal length
 The focal length is the distance from the focal point to the center of the lens
 Converging Lens
 A converging Lens is thicker in the middle. A converging lens will refract light waves so that they will “converge” to form an image.
 Also called a convex lens
 Converging Lens
 A converging lens can produce a real or virtual image
 When an object is located at a distance that is greater then the focal length, the image produced is real.
 Converging Lens
 When the object is located at a distance that is between the lens and the focal point, the image is virtual
 Diverging Lens
 A diverging lens is thinner in the middle. Rays of light that pass through a diverging lens will refract outward
 Also called a concave lens
 Diverging Lens
 A diverging lens will produce only virtual images
 The image produced will be smaller than the object
 The image will be inside of the focal point
 Examples of Converging and Diverging Lenses
 ThinLens Equation
 1/p + 1/q = 1/fp = distance from object to lensf = focal length
 q = distance from image to lens
 Where:
 Signs For Lensesp is negative when the object is in back of the lens
 p is positive when the object is in front of the lens
 Signs for lensesq is negative when the image is in front of the lens
 q is positive when the image is in back of the lens
 Signs for lensesf is negative for a diverging lens
 f is positive for a converging lens
 Example Problem
 An ant is placed 2 cm in front of a converging lens that has a focal length of 1 cm. What is another name for this lens? Where is the image located?
dvalde4@neisd.net
valde4@neisd.net
April 1
Mirrors lab
Finish thin lens intro ws
April 3
Goal: be able to solve for object distance, image distance, and magnification
Goal: be able to use ray diagrams to find the proper location of an image
Goal: understand the characteristics of lenses and mirrors and the images they produce
Demonstration of real and virtual images with a concave mirror and a candle
Thin lens ws
April 4
Goal: be able to solve for object distance, image distance, and magnification
Goal: be able to use ray diagrams to find the proper location of an image
Goal: understand the characteristics of lenses and mirrors and the images they produce
Thin lens labstudents will find the image location and size with a convex lens, candle, and a screen
April 5
Goal: be able to solve for object distance, image distance, and magnification
Goal: be able to use ray diagrams to find the proper location of an image
Goal: understand the characteristics of lenses and mirrors and the images they produce
Ray diagram notes
Lens rules for ray diagrams:
#1 Draw a ray of light from the top of the object to the center of the lens. This beam must be parallel to the principle axis. Once at the center of the lens, the beam will refract. Continue the line so that it goes through the focal point.
#2 Draw a ray of light from the top of the object so that it goes through the exact center of the lens.
Ray diagrams ws
April 6
Goal: be able to solve for object distance, image distance, and magnification
Goal: be able to use ray diagrams to find the proper location of an image
Goal: understand the characteristics of lenses and mirrors and the images they produce
Lens, mirrors, light concepts ws
Test delayed until April 10
April 7
Review light
Review ws due next class
Test April 10 class
April 10
Goal: be able to solve for object distance, image distance, and magnification
Goal: be able to use ray diagrams to find the proper location of an image
Goal: understand the characteristics of lenses and mirrors and the images they produce
Turn in review ws
Testlenses, light, mirrors
April 11
Goal: use coulomb’s law to solve for F, q, or d
Goal: understand how charges are transferred
Notesstatic electricity
 Electrostatics
 Charge
 There are two kinds of charges
 Positive
 Negative
 Charge
 Electrons are negatively charged
 Protons are positively charged
 Charge
 Like charges repel
Example: protons repel protons
 Unlike Charges attract
 Example: Protons attract electrons
 Charge
 Electric charge is conserved
 Charges can be transferred, but or not created nor destroyed
 Charge
 Electric Charge is quantized (it has a value).
 An electron has a charge of
1.6 x 10^{19} C
 Charge
 There are 6.2 x 10^{18} electrons in –1 C
 Transfer of Charge Conductors
 Conductor: material that transfers charge easily. Electrons are not held tightly to the nucleus
 Transfer of Charge Insulators
 Insulators: a material that does not transfer charge easily. Insulators hold their electrons more tightly. A poor conductor of electricity.
 Transfer of Charge Charging by Contact
 Charging by contact
 The transfer of electrical charges by objects in contact.
 Transfer of Charge Induction
 Induction: The charging of an object without direct contact from another object.
 Induction Example
 Transfer of Charge Induction
 Example of induction: A negatively charged rod is moved close to a metal sphere of neutral charge that is attached to Earth. The negative rod will repel the electrons in the sphere.
 Transfer of Charge Induction
 The electrons in the sphere will be repelled by the negatively charged rod and will move to the Earth. The sphere will have uniformly distributed positive charges on its surface.
 Transfer of Charge Polarization
 When a charged object is brought next to a neutrally charged insulator, polarization occurs.
 Transfer of Charge Polarization
 Polarization: The presence of a charged object will cause another object’s charges to realign. One side of the object will be more positive and the other more negative.
 Grounding
 An object is considered to be grounded if it is attached to the Earth.
 Grounded: attaching an object to the Earth to eliminate excess charge.
 Coulomb’s Law
 F = k q_{1}q_{2}
_{ }r^{2}
Where k = 8.99 x 10^{9 }N m^{2} / C^{2}
 Coulomb’s Law Example Problem
A large harvester ant has accumulated 6 mC of charge. A large atta major has accumulated 10 mC. The atta is to the left of the harvester. The two ants are separated by 2 cm. What is the force on the atta ant?
April 12
Goal: use coulomb’s law to solve for F, q, or d
Goal: understand how charges are transferred
Coulombs law ws
April 13
Goal: use coulomb’s law to solve for F, q, or d
Goal: understand how charges are transferred
Statics demo
April 17
Current electricity and circuits notes
 CURRENT ELECTRICITY
 Current
Electric Current (I) A flow of charged particles, usually electrons. Units for I are amperes (A or amps).
Current that flows in one direction is direct current (DC)
Current that alternates direction is alternating current (AC)
 Potential Difference
 Another term for potential difference (V) is voltage (V)
 Unitsvolts (V)
 The voltage measures the electric potential difference between two points.
 Electric current will flow from high to low potentialthe greater the difference, the greater the electron flow.
 Potential Difference Sources Examples
Voltaic Cell dry cell that converts chemical energy into electric energy.
Battery several dry cells together to produce electric energy from chemical energy
Photovoltaic solar cell, converts light energy to electric energy.
Generators, power plants
 Ohm’s Law
Resistance property that determines how much current will flow .
Ohm’s Law Equation: I = V/R or V = IR
Resistance = Voltage / Current
Units for resistance = Ohm’s W
Resistors devices designed to have a specific resistance. Ex. Potentiometer (variable resistor or rheostat)
 Ohm’s Law continued
 Conductors have little resistance to electron flow
 Insulators have great resistance to electron flow.
 Electric Circuit
Electric Circuit charges moving around a closed loop from a pump(battery) back to the pump.
There are two basic types of circuits:
series and parallel.
There is only one path or branch for electron flow in a series circuit. There are multiple branches or paths in a parallel circuit.
.
 Electric Power
Electric Power the product of voltage x current.
Equation: P = V x I
Power = Voltage x Current Units: Watts
The unit for current is the ampere.
1 ampere = 1 Coulomb/ second
Found by a French scientist Andre Ampere
 Energy Transfers in Circuits
Equation: Power = Current^{2} x Resistance
When a capacitor is charged or discharged through a resistor, the current is high initially and falls to 0
The energy transferred is the product of power and time.
Equation: Energy = I^{2}Rt
 Transmission of Electric Energy
High voltage transmission lines carry electrical energy over long distances with minimal loss of energy. Ex. Power Plants
The kilowatthour is a unit of energy.
Energy = Power x time (units: kilowatthour)
April 18
Circuits notes:
The electric current in a series circuit has only one path to follow. This means that the current at any point in a series circuit is the ____________________________
Example of a series circuit:
 The total resistance of the circuit.
 The total current flowing through the circuit
 Fill in the chart using ohm’s law:
R
I
V
P
 The voltage drop across the 2 W resistor
 the current through the 3 W resistor
Parallel Circuits
Any resistors connected in parallel connect to the same two points. Therefore, resistors connected in parallel have the same ________________________.
Find the equivalent resistance of the circuit
Fill in the chart using ohms law:
R
I
V
P
What is the potential difference across the 4 W resistor?
What is the current through the 2 W resistor?
Review:
When you add a resistor in series the total resistance of a circuit ___________________
When you add a resistor in parallel, the total resistance of a circuit ________________
Adding a resistor in series will ____________________ the current through the circuit
Adding a resistor in parallel will ______________the current flowing through the circuit
Three light bulbs are connected in a series. One burns out. The other two ___________
Three light bulbs are connected in parallel. One burns out. The other two ___________
April 19
Current electricity ws
April 21
Review circuits
Series and parallel ws
Electricity testMay 8^{th}?
Review ws
April 24
Review static electricity
Coulombs law II ws
Test on May 8^{th}
April 25
Notescompound circuits (complex circuits)
Assignment CD 341
Assignment CD 342
April 26
***You may use one 3x5 note card on the final exam. All information on the note card must be written by your own hand.***
Notesreview comound circuits
Assignment CD 351
Assignment CD 352
April 27
Circuits lab
May 1
Review electricity
May 2
Compound circuts Ifinding the current and resistance of individual resistors
May 3
Compound circuts IIfinding the current and resistance of individual resistors3 problems
Test on Tuesday( May 15)
May 4
Notesthermodynamics
Specific heat ws
Electricity test on May 15
May 8
Review electricity and review ws
Test next class
Please bring book on may 16
May 9
Testelectricity
Please bring book next class
May 10
Fusion and fission assignmentuse with book
May 11
Notesmagnets
May 12
Magnets I ws
May 15
Magnetic field notes, diagram, and demonstration
May 16
NotesPhotoelectric effect
May 17
Notesthermodynamics
May 18
Convection, conduction, radiation demo
Heat energy assignment
May 19
Work on the semester exam review sheet
May 21
Work on the semester exam review sheet
May 22