(i) Define amplitude and wavelength of a sound wave.
(ii) A displacement–distance graph of a sound wave shows successive compressions at positions x=1.2m and x=2.0m. The maximum displacement of particles from the mean position is 4mm. Write the numerical values of the wavelength and amplitude represented by the graph.
(iii) Another sound wave travelling in the same medium has the same wavelength but double the amplitude. Explain how its loudness will compare with the first wave.
(iv) A third wave has half the wavelength but the same amplitude as the first wave. Explain how its pitch will compare with that of the first wave.