Introduce wavelength and amplitude for longitudinal and transverse waves, Show that wavespeed depends on the medium and frequency depends on the source, Introduce the wave equation

1. 10 October 2010 6.2 Describing Waves Write down two similarities between longitudinal and transverse waves Write down two differences Give an example of each

2. Aims Introduce wavelength and amplitude for longitudinal and transverse waves Show that wavespeed depends on the medium and frequency depends on the source Introduce the wave equation

3. x amplitude t Wavelength

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

6. 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

7. 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

8. 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

10. Can we figure the equation out?

12. Where: v = speed of wave / m/s f = frequency of wave / Hz (1/s) λ = wavelength of wave / m

13. How can we prove this? What would happen if we increased the wavelength of a wave? What would happen if we decreased the wavelength of a wave?