(a)[1]
Underline two further examples of transverse waves: seismic P-waves, seismic S-waves, sound, X-rays.
(b(i))[3]
Fig. 5.1 shows a wooden bar and a glass block in a ripple tank. The water depth in the tank is smaller than the height of the glass block. The wooden bar oscillates up and down once every $0.15\,\text{s}$ so that crests are produced. The speed of the water wave is $27\,\text{cm s}^{-1}$. Calculate the frequency and the wavelength of the wave.
(b(ii))[2]
Diffraction occurs at the right-hand edge of the glass block. On Fig. 5.1, draw two crests after they emerge from the glass block to show the diffraction.
(b(iii))[1]
Describe how a wave with a smaller wavelength is produced using the wooden bar.
(b(iv))[1]
Describe how diffraction is affected when the wavelength decreases.