1. CHAPTER 25
Vibration & Waves

2. Label the parts of this transverse wave: crest, trough, amplitude, wavelength
crests: highest points trough: lowest points
amplitude: midpoint to crest or trough
wavelength: distance from crest to crest (trough to trough)

3. What is the source of all wave motion?
Vibrations

4. What is the period of a pendulum or a wave??
The time it takes for a wave to make one complete cycle (pendulum: forward and back swing).

5. What is the unit of frequency?
Hertz

6. What is the difference between a transverse wave and a longitudinal wave?
Transverse wave  source of motion goes up and down or side to side (right angle)
Longitudinal wave  source of motion in same direction as wave motion

7. How do particles move in a transverse wave? Longitudinal wave?
Transverse  perpendicular
Longitudinal  same direction

8. Which type of wave is sound, transverse or longitudinal?

9. What is interference?
When two or more waves are at the same place at the same time.

10. What are the two types of interference?
Constructive: crest and crest or trough and trough resulting in an increase in amplitude
Destructive: crest and trough (out of phase): cancels out

11. Where is the node? An antinode? What kind of a wave is this?
The lowest points. The highest points.
A standing wave. It results from interference.

12. What is a node?
Any part of a standing wave that remains stationary.

13. Why does the pitch of a siren of an ambulance change as it passes you
Why does the pitch of a siren of an ambulance change as it passes you? What is this called?
As the car approaches you, the waves are closer together and have a higher frequency. As the ambulance passes you, the waves are farther apart and the frequency is lower.

14. Doppler Effect only occurs when…
The source of sound is moving or you are moving.

15. True/False Speed varies within a wave.
False! It stays the same when it’s in the same medium.

16. Does the medium/material move when a wave travels through it?
NO, the wave only creates a disturbance.

17. What is the relationship between frequency and period?
·Frequency = 1/period
Period = 1/ frequency

18. If you triple the frequency of a vibrating object, its period
Decreases by 3

19. What happens to wavelength when frequency INCREASES?
It gets SHORTER

20. What happens when an airplane travels faster than the speed of sound?
It creates a sonic boom

21. What is the formula for wave speed?
Wave speed = wavelength x frequency

22. A tuning fork has a frequency of 140 Hz and the wavelength of the sound produced in 2 meters. Calculate the speed of the wave.
2 m x 140 Hz = 280 m/s

23. What is a standing wave?
Wave in which parts of the wave remain stationary and the wave appears not to be traveling The reflected wave interferes with the incoming wave.