1. Plan for Today (AP Physics 1)
Class Review

2. Know and be able to apply Hooke’s Law
F = -kx
Force = spring constant * displacement
Negative means that the force opposes (opposite direction) of the displacement
Be able to solve for each part

3. Equations of motion for simple harmonic oscillators
V and a as a function of x, and x and v as a function of t
Remember: for function of t, mode MUST be in radians to work

4. Periodic of a SHM Spring mass system Pendulum
Equation:
Pendulum
Be able to solve for various parts

5. Describe the parts of longitudinal and transverse waves
Vibration parallel to motion
Has compressions (close together) and rarefactions (far apart)
Transverse
Vibration perpendicular to motion
Crests (high part) and troughs (low part)
Around equilibrium position (halfway between crest and trough)
Wavelength – from crest to crest/trough to trough

6. Damped Harmonic Motion
Big idea – gets less and less (because of friction/real life variables) - but for whatever is in harmonic motion, the period should stay the same

7. Speed of Waves on a String
V = wave length * frequency
V = wavelength/period

8. Superposition and Interference
Superposition – when waves are coming together
Interference
Constructive – same phase, get bigger
Destructive – opposite phase, subtract
Can be complete if they are exactly the same

9. 1. Hooke’s Law Example Problem
A rubber band stretches 5 cm when a 15 g mass is attached to it.
What is the spring constant of the rubber band?
How far would the rubber band stretch if a 50 g mass was attached?

10. 2. Example problem for equations of simple harmonic oscillation
An object is in simple harmonic motion according to the following equation (assume distances are in m)
X = 4 * cos (3 * pi * t)
What is the amplitude?
What is the period of the motion?
Write the equation for the acceleration of the system
What is the object’s displacement at t = 1.2 s?

11. 3. Example Problem for Period of SHM
A spring mass system has a mass of 1.5 kg and a spring constant of 53 N/m. The maximum displacement is 25 cm. Find
The period
The frequency
The velocity at 12 cm from equilibrium

12. 4. Example Problem
Sketch a period of

13. 5. Example with Longitudinal and Transverse Waves
Compare and contrast longitudinal and transverse waves

14. 6. Example Problem for Speed of Waves
A rope is 10 m long and has a mass of 0.5 kg. A wave on it has a velocity of 8 m/s. What is the tension of the rope?

15. 7. Example Problem with Superposition and Interference
Sketch examples of constructive interference and complete destructive interference before, during, and after the waves meet

16. Answer to 1
K = 2.94 N/m
X = .17 m or about 17 cm

17. 2. Answer
A = 4 m
T = .67 s (f = 1.5 Hz)
a = - 4 * (3 pi)^2 * cos (3 * pi * t)
X = 1.23 m

18. 3. Answers
T = 1.06 s
f = .95 Hz
V = 1.3 m/s

19. 4. Answer

20. 5. Answer
Longitudinal waves – particle motion is parallel to the motion of the wave, consists of compressions and rarefactions
Sound waves
Transverse waves – particle motion is perpendicular to the wave motion, typical sine wave look
Light waves

21. 6. Answer
3.2 N

22. 7. Answer
Constructive Interference

23. 7. Answer
Complete destructive interference