Fig. 5.1 is a diagram showing the arrangement of air particles as a longitudinal wave passes through them. [Figure 5.1] On Fig. 5.1, mark the centre of a compression with the letter C, and mark the centre of a rarefaction with the letter R.

1. (a)(i)Fig. 5.1 is a diagram showing the arrangement of air particles as a longitudinal wave passes through them. [Figure 5.1] On Fig. 5.1, mark the centre of a compression with the letter C, and mark the centre of a rarefaction with the letter R.[1]
2. (a)(ii)Describe the difference between a compression and a rarefaction.[1]
3. (b)(i)In a ripple tank, a water wave is produced by a wooden bar moving up and down on the surface of water. The wooden bar makes 45 complete oscillations in 1.0 minute. Calculate the frequency of the wave produced. frequency = .................................................... Hz[1]
4. (b)(ii)The frequency of the water wave is increased by moving the wooden bar up and down more quickly. State what happens to the speed and what happens to the wavelength of the wave produced. speed .................................................... wavelength ....................................................[2]
5. (b)(iii)The crests of the water wave move into the shallow region shown in Fig. 5.2. [Figure 5.2] On Fig. 5.2, draw the crests in the shallow region.[2]
6. (c)Describe what is meant by the diffraction of a water wave.[1]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.