A sound wave moves with a speed of 320 m/s through air. The variation with time of the displacement of an air particle due to this wave is shown in the graph.
Which statement about the sound wave is correct?
A The frequency of the wave is 500 Hz.
B The graph shows that sound is a transverse wave.
C The intensity of the wave will be doubled if its amplitude is increased to 0.4 mm.
D The wavelength of the sound wave is 1.28 m.
A wave of frequency 15 Hz travels at 24 m/s through a medium. What is the phase difference between two points 2 m apart?
A There is no phase difference.
B They are out of phase by a quarter of a cycle.
C They are out of phase by half a cycle.
D They are out of phase by 0.8 of a cycle.
A wave of amplitude a has an intensity of 3.0 W.m^2. What is the intensity of a wave of the same frequency that has an amplitude 2a?
A 4.2 W/m^2
B 6.0 W/m^2
C 9.0 W/m^2
D 12 W/m^2
The graph shows the variation with time of displacement for two different waves X and Y. Wave X has frequency f and amplitude A. What is the frequency and what is the amplitude of wave Y?
f = 1/2 f, amplitude = 1/2 A
f = 1/2 f, amplitude = 2 A
f = 2f, amplitude = 1/2 A
f= 2f, amplitude = 2 A
A loudspeaker emits a sound wave into a tube initially full of water. A tap at the bottom of the tube is opened so that water slowly leaves the tube. For some lengths of the air column in the tube, the sound heard is much louder. The first loud sound is heard when the air column in the tube has length x. The next time that a loud sound is heard is when the air column in the tube has length y. What is the wavelength of the sound wave from the loudspeaker?
2x
4y
2(y – x)
4(y – x)
A source of sound of frequency 1000 Hz directly approaches a stationary observer. The observer measures the frequency of the received sound to be 1500 Hz. The speed of sound in still air is 330 m.s^–1. What is the speed of the source of sound?
110 m.s^–1
165 ms^–1
220 m.s^–1
330 ms^–1
The graph shows how the intensity of electromagnetic radiation emitted from a distant star varies with wavelength. In which region of the electromagnetic spectrum is the radiation of greatest intensity?
infrared
visible light
ultraviolet
X-ray
Which statement concerning a stationary wave is correct?
All the particles between two adjacent nodes oscillate in phase.
The amplitude of the stationary wave is equal to the amplitude of one of the waves creating it.
The wavelength of the stationary wave is equal to the separation of two adjacent nodes.
There is no displacement of a particle at an antinode at any time.
Which waves would best demonstrate diffraction through a doorway?
sound waves
ultraviolet waves
visible light waves
X-rays
Two loudspeakers are placed near to each other and facing in the same direction. A microphone connected to an oscilloscope is moved along a line some distance away from the loudspeakers, as shown. Which statement about the waves emitted by the loudspeakers is not a necessary condition for the microphone to detect a fixed point along the line where there is no sound?
The waves must be emitted in phase.
The waves must be emitted with a similar amplitude.
The waves must have the same frequency.
The waves must have the same wavelength.