1. What is a wave? Definition: a disturbance in space and time
Waves transfer energy
Medium: substance that waves travel through.
Waves travel fastest in solids
Waves travel slowest in gas
What causes waves? Vibration of molecules

2. Types of waves Transverse waves – ocean waves, light waves, radio
Parts:
Crest – high point
Trough – low point
Longitudinal waves – sound waves
Parts
Compression – high pressure
Rarefaction – low pressure

3. Compression
Rarefaction
Crest
Amplitude
Trough

4. Basic wave properties All waves have 4 basic properties
Amplitude – The height of a wave
Wavelength – the distance between crests or compressions Length of one wave (“S” shape)
Frequency – how often a wave occurs in a time frame (cycles/sec, wiggles/sec, ) Hertz
Velocity – how fast a wave can occur in a time span

5. Amplitude
Height (volume) of crest or trough from Equilibrium point, measured in decibels (db)
the total energy of the wave
Amplitude or

6. Wavelength and frequency are inversely proportional to each other.
Longer wavelength / Lower frequency
Shorter wavelength / Higher frequency

7. Practice Questions
Which label on the model to the right, represents a wavelength?
A.) Q
B.) R
C.) S
D.) T

8. Frequency The number of wave crests that pass one place each second.
(Measured in Hertz)
Ex. The frequency of vibrations gives the pitch on a guitar string
Which wave has a higher frequency? A. B.

9. Practice Questions
What would be the wavelength in centimeters of the wave, illustrated above, if its frequency were doubled?
A.) 2.5
B.) 0.8
C.) 0.625
D.) 0.4

10. Velocity of a Wave (Wave speed)
V = ג x f
Wavelength X Frequency
Velocity = m/s
Wavelength (ג) = meters
Frequency = hertz
(cycles/second)

11. Practice Questions
1. A wave has a wavelength of 15 cm and has a frequency of 10 waves/second. What is the speed of the wave?
The speed of a wave on a rope is 50cm/s and it’s wavelength is 10cm. What is it’s frequency?
A wave is traveling with a velocity of 125m/s and has a frequency of 20 waves/second. What is the length of the wave?

12. Practice Questions
1. A wave has a wavelength of 15 cm and has a frequency of 10 waves/second. What is the speed of the wave? cm/s
The speed of a wave on a rope is 50cm/s and it’s wavelength is 10cm. What is it’s frequency? 5 Hz
A wave is traveling with a velocity of 125m/s and has a frequency of 20 waves/second. What is the length of the wave? m

13. Which wave has the greatest velocity?
Practice Question
Which wave has the greatest velocity?
V = f x ג
2m x 8Hz = 16 m/s
Velocity = m/s
Wavelength (ג) = meters
Frequency = hertz
(cycles/second)