A hollow tube is set up to study stationary waves. One end of the tube is closed, while the other end is open. A loudspeaker linked to a signal generator is positioned close to the open end of the tube, as shown in Fig. 6.1. The tube has length $L$. The frequency of the signal generator is adjusted so that the loudspeaker produces a progressive wave of frequency $440\,\text{Hz}$. A stationary wave is formed in the tube. A representation of this stationary wave is shown in Fig. 6.1. Two points P and Q on the stationary wave are labelled.
(a(i))[1]
Describe the difference between a progressive wave and a stationary wave in terms of energy transfer.
(a(ii))[3]
Explain the process by which the stationary wave is formed in the tube.
(a(iii))[1]
State the direction of oscillation of an air particle at point P.
(b)[1]
On Fig. 6.1, use the letter N to label the nodes of the stationary wave.
(c)[1]
State the phase difference between points P and Q on the stationary wave.
(d(i))[2]
The speed of sound in the tube is $330\,\text{m s}^{-1}$. Calculate the wavelength of this sound wave.
(d(ii))[2]
The speed of sound in the tube is $330\,\text{m s}^{-1}$. Calculate the length $L$ of the tube.
Worked solution & mark scheme
This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Progressive wave carries energy; stationary wave has no net energy transfer” …