basic introduction to waves

1. What is a wave?
29 January 2015
How many types
of wave have you
heard of in
everyday use?
Do they have
anything in
common?

2. Aims
• Describe the origin of a wave
• Explain the properties of a wave

3. Key terms
• Displacement: how far the
wave is disturbed from its rest
position
• Oscillation: a complete to and
fro movement; this could be
going up and down or
sideways

4. What is a wave?
A wave is a
disturbance
moving through a
material

5. What causes a wave?
• The source of a wave
is always something
that vibrates
• The material that the
wave travels through
is called the medium

10. Amplitude, A
• The maximum distance that each point in the
medium moves from its normal position as
the wave passes
• Measured in metres, m

11. Frequency, f
• This is the number of waves that pass any
point in the medium every second, so it is the
same as the number of vibrations per second
• Frequency is measured in per seconds or
hertz, 1/s, s-1 or Hz

12. Wave speed, v
• This is the speed at which each wave crest
moves through the medium.
• Measured in metres per second, m/s or ms-1

13. Wavelength, λ
• This is the length of a complete wave
measured from any point to the next identical
point – the distance is always the same no
matter which point you choose
• It is measured in metres, m

14. Wavelength, λ
• This is the length of a complete wave
measured from any point to the next identical
point – the distance is always the same no
matter which point you choose
• It is measured in metres, m

15. fv 
Where:
v = speed of wave / m/s
f = frequency of wave / Hz (1/s)
λ = wavelength of wave / m

16. How can we prove this?
1
1
330
330





msf
msv
fv


What would happen if we increased the wavelength of a wave?
What would happen if we decreased the wavelength of a wave?

26. Assessment activity 2.6
• Discuss how you could model the movement
of a wave (P3)
• Construct your model or role play it to
another group
• REMEMBER: the longer the wavelength, the
smaller the frequency. When calculating
speed, make sure you change the prefixes