(a)[2]
Explain what the principle of superposition means.
(b)
Sound waves go from the source S to point X by two routes, SX and SPX, as shown in Fig. 5.1.
(b(i)1)[1]
State the phase difference at X between these waves for a minimum to occur.
(b(i)2)[1]
State the phase difference at X between these waves for a maximum to occur.
(b(ii))[2]
The sound from S has a frequency of $400\,\text{Hz}$ and the speed of sound is $320\,\text{m s}^{-1}$. Calculate the wavelength of the sound waves.
(b(iii))[2]
The distance SP is $3.0\,\text{m}$ and the distance PX is $4.0\,\text{m}$. The angle SPX measures $90^\circ$. Suggest whether point X shows a maximum or a minimum. Explain your answer.