1. Water waves have two features common to all waves:
14.2 Wave Motion
Water waves have two features common to all waves:
1. A wave is a traveling disturbance
2. A wave carries energy from place to place

2. 14.2 Wave Motion
Each particle of a wave merely oscillates about an equilibrium point (no bulk flow of water)
The wave moves but it does not carry matter with it (it travels through a medium)

3. 14.2 Wave Motion
A single wave pulse shows that it is begun with a vibration and transmitted through internal forces in the medium.

4. 14.2 Wave Motion
If the wave moves up and down at the same rate, a periodic wave is generated (note point P)

5. 14.2 Wave Motion
Transverse Wave
A transverse wave is one in which the disturbance is perpendicular to the direction of travel of the wave

6. 14.2 Wave Motion

7. Cycle – a wave is a series of many cycles (a complete vibration)
14.2 Wave Motion
Wavelength (λ) – horizontal length of one cycle. The distance between successive crests, troughs, or any two successive points.
Amplitude
crest
trough
Cycle – a wave is a series of many cycles (a complete vibration)

8. 14.2 Wave Motion
Period (T) – The time required for one complete up/down cycle (vibration). The time to travel one wavelength.
Frequency (Hz)
f = 1 __ T
period and frequency depend only on the source of the wave, NOT on the speed or medium

9. Longitudinal Wave Rarefaction
14.2 Wave Motion
Rarefaction
Longitudinal Wave
A longitudinal wave is one in which the disturbance is parallel to the line of travel of the wave
Sound waves are longitudinal waves

10. 14.2 Wave Motion

11. 14.2 Wave Motion
Rarefaction

12. 14.2 Wave Motion

13. 14.2 Wave Motion
A simple relation exists between period, wavelength, and the speed of a wave.
v = λ __ T
= fλ
v = f λ
Speed of a Wave

14. 14.2 Wave Motion

15. 14.2 Wave Motion
A 2640 Hz whistle produces sound waves that have a wavelength of 50.0 cm in water. Find the speed of sound in water.

16. 14.2 Wave Motion
A piano emits frequencies that range from a low of about 28 Hz to a high of about 4200 Hz. Find the range of wavelengths in air attained by this instrument when the speed of sound in air is 340 m/s.

17. - What is the wavelength of the disturbance?
14.2 Wave Motion
An 855 Hz disturbance moves through an iron rail at a speed of 5130 m/s.
- What is the wavelength of the disturbance?
- What is the period of the disturbance?

18. 14.2 Wave Motion
Which parts of a longitudinal wave correspond to the troughs and crests of a transverse wave?
Assuming that the waves pictured are moving at the same speed, what is the relationship of their
frequencies?
What is the relationship between the direction a wavelength is measured and the direction the
amplitude is measured for each wave pictured?
As pictured, are these waves in phase or out of phase?