This document defines key terms related to waves, including transverse and longitudinal waves. It explains that waves can transfer energy and information through a medium without the medium itself moving. Transverse waves involve oscillations perpendicular to the direction of energy transfer, while longitudinal waves involve oscillations parallel to it. Key wave measurements are defined, such as amplitude, wavelength, frequency, and period. The relationship between these variables is described by the wave equation, which relates wave speed, frequency, and wavelength. Examples are given of different types of waves and questions are provided for students to practice using the wave equation.

1. Draw me a wave!
YouTube - Water bubble in Space (zero gravity)

2. Learning Outcomes
Everyone should:
•Define a wave
•Differentiate between longitudinal and transverse waves (with
examples)
Most will:
•Define amplitude, wavelength, frequency and period of a wave
•Describe the relationship between frequency and period
Some might:
•Use the wave equation

3. Waves
Waves can transfer energy and
information without a net motion of the
medium through which they travel.
They involve vibrations (oscillations) of
some sort.

4. Rays
Rays indicates the direction of energy
transfer.

5. Transverse waves
The oscillations are perpendicular to
the direction of energy transfer.
Direction of energy transfer
oscillation

6. Transverse waves
Peak/crest
trough

7. Transverse waves
• Water ripples
• Light
• On a rope/slinky
• Earthquake

8. Longitudinal waves
The oscillations are parallel to the direction
of energy transfer.
Direction of energy transfer
oscillation

9. Longitudinal waves
compression
rarefraction

10. Longitudinal waves
• Sound
• Slinky
• Earthquake

11. Wave measurements

12. Amplitude - A
The maximum height of the wave from
the middle line position.
amplitude

13. Frequency - f
The number of complete waves
(oscillations) in one second. Measured in
Hertz.
50 Hz = 50 vibrations/waves/oscillations in one second.

14. 1 2
0
2
1
1
2
Height
(m)
Time (s)
Frequency – The number of
waves per second. If one wave
passes in one second it has a
frequency of one Hertz or Hz. This
is the unit of frequency.

15. Wavelength - λ
The length of one complete wave.
wavelength

16. Wave speed - v
The speed at which the wave fronts
pass a stationary observer.
330 m.s-1

17. The Wave Equation
V = speed of wave (m/s)
f = frequency of wave (Hz)
λ = wavelength (m)
v = fλv
λf x

18. 1) A water wave has a frequency of 2Hz and a wavelength of
0.3m. How fast is it moving?
2) A water wave travels through a pond with a speed of 1m/s
and a frequency of 5Hz. What is the wavelength of the
waves?
3) The speed of sound is 330m/s (in air). When Dave hears
this sound his ear vibrates 660 times a second. What was
the wavelength of the sound?
4) Purple light has a wavelength of around 6x10-7
m and a
frequency of 5x1014
Hz. What is the speed of purple light?
Group wave equation questions
0.2m
0.5m
0.6m/s
3x108
m/s

19. Wave equation questions
v
λf x