1. Chapters 11-12 Vibrations and Waves; Sound

2. 11-1 Simple Harmonic Motion Vibrate/Oscillate = goes back and forth Periodic = same amount of time Equilibrium position (of a spring) is where there is no net force Displacement is the distance form the equilibrium position Amplitude is the maximum displacement A cycle is one complete motion

3. Period is the time to complete one cycle Frequency is the number of cycles per unit time (usually seconds) SHM = simple harmonic motion SHO = simple harmonic oscillator

4. 11.2-11.3 Energy in SHO and Period/Sinusoidal Nature of SHM

5. 11.4 Simple Pendulum A simple pendulum is a bob at the end of cord that does not stretch

6. 11.5 Damped Harmonic Motion Damping = slowing over time Underdamped = many swings before coming to rest Overdamped = damping so large, takes time to reach equilibrium Critical damping = equilibrium in shortest time

7. 11-6 Forced Vibrations; Resonance Forced vibration = a vibration with an external force Natural Frequency = Resonant Frequency is the frequency that an object innately has Resonance is when the forced frequency is equal to the natural frequency of the object. The wave then builds in amplitude

8. 11-7 Wave Motion Mechanical waves need a medium Waves transfer energy Pulse is a part of a wave Continuous/Periodic wave = a wave that has a continuous source (more than just a pulse) Know crest, trough, amplitude, wavelength, frequency, period, wave velocity, wave equations (from chem)

9. 11-8 Types of Waves Transverse = perpendicular oscillations Longitudinal = disturbance and wave speed are parallel Surface waves are a combination (earthquakes and ocean waves are of this variety)

10. 11-10 Intensity Related to Amplitude and Frequency Intensity = power transported across unit area perpendicular to the direction of energy flow 11-9 is next

11. 11.9 Energy Transported by Waves

12. 11-11 and 11-12 Transmission and Reflection of Waves; Interference/Principle of Superposition Waves reflect at boundaries –Inverts amplitude Waves also reflect at boundaries –Initial angle with normal is the same before and after reflection Principle of Superposition = waves add algebraically (displacements) –Constructive = in phase; destructive = out of phase

13. 11-13 Standing Waves; Resonance Know Standing Wave, node, antinode, resonant (natural) frequency Fundamental is the first harmonic Overtones begin at the second harmonic Harmonics are found by multiplying the fundamental frequency by an integer

14. 11-14 Refraction and 11-15 Diffraction Refraction = bending of a wave due to a change in medium (and thus speed) Diffraction = spreading of a wave due to an obstacle

15. 11-16 Mathematical Representation of a Traveling Wave

16. Problems Pages 316-321 Demonstrate P: 3, 6, 9, 26, 28, 36, 47 Questions: 2, 5, 7, 8, 9, 12, 19 Problems: 4, 5, 10, 21, 29, 30, 34, 37

17. 12-1 Characteristics of Sound Speed of sound is 343 at room temperature in the medium of air Loudness is a measure of intensity Pitch is a measure of frequency Audible range is from 20 to 20,000 Hz Ultrasonic or Infrasonic are above or below the audible range Sound is a pressure wave

18. 12-5 and 12-6: Quality of Sound, and Noise; Superposition and the Interference of Sound Waves Quality of sound = timbre, tone color and can be related to the number of overtones heard Destructive interference occurs when the path length difference is ½ off Constructive interference occurs when the difference in path length is exactly Beats occur when the difference in frequency is less that 10 Hz

19. 12-7 Doppler Effect 12-8 Shockwaves and Sonic Boom Objects traveling towards an observer have a higher observed frequency Objects traveling away from an observer have a lower observed frequency A shockwave occurs when waves pile up in front of you, then you exceed the speed of those waves When you break the sound barrier, a sonic boom is how the energy is heard and this boom is “pulled” through the air similar to water being pulled behind a boat when it is traveling faster than the waves it produces

20. Chapter 12 Homework Pages 346-352 Question 4 Problems 1 and 78

21. Problems Pages 316-321 Demonstrate P: 3, 6, 9, 26, 28, 36, 47 Questions: 2, 5, 7, 8, 9, 12, 19 Problems: 4, 5, 10, 21, 29, 30, 34, 37