1. Define “wave”
Explain why there is no sound in space
Define “period”
What is the unit for period?
Define “frequency”
What is the unit for frequency?

2. Wave is ‘transfer of energy’
The energy is transferred through particles, which are called the ‘medium’ of the wave.
The particles of medium are not transferred along the wave.

6. Longitudinal wave motion vs. Transverse wave motion
Longitudinal – The vibration and the wave motion are parallel
Transverse – The vibration
and the wave motion are perpendicular

7. Amplitude
Trough
Crest
Wavelength
Period
Frequency
Wave speed

8. Frequency: Period: The number of waves passing in one second.
Unit: hertz (Hz)
Period:
The time taken for one wave to completely pass.
Unit: seconds

9. Frequency & Period 2 waves in one second. 15 waves in two seconds.
30 waves in ten seconds.
15 waves in one minute.
240 waves in one minute.

10. Frequency and Period
Hz = s-1

11. Find the period.
Find the frequency.
Find the wave speed.

12. How do you calculate the speed?

13. Wave Equation λ = wavelength (m) T = period (s) f = frequency (Hz)
v = wave speed (ms-1)

14. Try this – SHOW ALL WORKING
Sally is in the middle of the sea. She counted 12 waves passing by in 5 seconds. If the waves have a wavelength of 1.6 m, calculate:
Period
Frequency
Wave speed

15. Try this – SHOW ALL WORKING
Ben is flicking a slinky to produce a continuous waveform.
If the waves are travelling at 2.7 ms-1 and the crests are 35 cm apart, calculate the time taken for one wave to pass a point.