In Fig. 10.1 the vertical lines represent the crests of a wave in a ripple tank. [Figure 10.1] Fig. 10.1 is drawn to scale, with 1.0 cm on the diagram representing 4.0 cm in the tank. A crest takes 2.0 s to travel from P to Q.

1. (a)(i)Determine the wavelength of the wave in the ripple tank.[2]
2. (a)(ii)Define the term frequency.[2]
3. (a)(iii)Determine the frequency of the wave.[1]
4. (a)(iv)The wave generator is a bar of wood. Describe how it is used to produce the wave shown.[2]
5. (a)(v)Some water in the ripple tank is removed. The water becomes less deep. No other change is made. State how the change in depth affects the wavelength and the speed of the wave.[1]
6. (b)(i)A student reads in a textbook that the speed of sound in air is about 300 m/s. He plans an experiment to check this value. He asks another student to stand a long distance away in a large open space. One student has a starting pistol. The pistol, when fired, produces a loud sound and a puff of smoke at the same instant. Other pieces of apparatus are needed for this experiment in order to measure the speed of sound. Name two other pieces of apparatus that are needed.[2]
7. (b)(ii)Describe how all the measurements are made.[3]
8. (b)(iii)State typical values for the speed of sound in: 1. a liquid 2. a solid.[2]

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