CIE A Level Physics

Topic Questions

Syllabus Edition

First teaching 2020

Last exams 2024

|

7.1 Waves: Transverse & Longitudinal

1
Sme Calculator
5 marks

Circular water waves are produced by vibrating dippers at points P and Q, as illustrated in Fig. 4.1.

q4b-paper-2-specimen-2022-cie-ial-physics

Fig. 4.1 (not to scale)

The waves from P alone have the same amplitude at point R as the waves from Q alone. Distance PR is 44 cm and distance QR is 29 cm.

The dippers vibrate in phase with a period of 1.5 s to produce waves of speed 4.0 cm s–1.

i)
Calculate the wavelength of the waves.



wavelength = .................................................... cm [2]

ii)
Calculate the path difference at point R of the waves from P and Q.

Give your answer in terms of the wavelength λ of the waves.



path difference = ....................................................... λ [1]

iii)
Describe the motion, if any, of the water particles at point R.
 
Explain your answer.

[2]

Did this page help you?

2a
Sme Calculator
2 marks

A wave on the surface of a ripple tank moves from the source at the rear of the tank to the front. The graph in Fig. 1.1 shows the variation with distance x of the displacement y of the surface of the water.

The solid line shows the displacement at t = 0 and the dashed line shows the displacement at t = 0.154 s.

q1ab_travelling-waves_ib-sl-physics-sq-medium

Fig. 1.1

Describe the difference between transverse and longitudinal waves.

2b
Sme Calculator
4 marks

Calculate for the wave on the ripple tank   

i)
the speed
[2]
ii)
the frequency
[2]
2c
Sme Calculator
3 marks

The graph in Fig. 1.1 shows the motion of the water waves at a point where displacement ≤ 6.0 cm.

Describe the appearance of the wave after being displaced by twice this distance.

2d
Sme Calculator
3 marks

The initial amplitude of the ripples is 0.38 cm.

Sketch a graph of displacement against time to show the motion of the surface of the water for the first 3.0 s.

Did this page help you?

3a
Sme Calculator
2 marks

Explain what is meant by a progressive wave.    

3b
Sme Calculator
4 marks

An elastic cord is fixed at one end and attached to a mechanical oscillator at the other end. Fig. 1.1 shows, at time t = 0, the shape of a section of the cord as the wave travels from left to right. W, X, Y and Z are four marked points on the cord.

7-1-3b-m-waves-graph-1

The mechanical oscillator has a steady frequency of 5.0 Hz. The wave has a wavelength of 0.60 m and an amplitude of 0.030 m.

On the axes of Fig. 1.2 sketch the graph of the displacement of point X over the period t = 0 to 0.40 s. Add suitable scales to the axes.

7-1-3b-m-waves-graph-2
3c
Sme Calculator
2 marks

For time t = 0, state which of the points W, X, Y and Z   

i)
is instantaneously at rest
[1]
ii)
has the greatest speed
[1]
3d
Sme Calculator
2 marks

The speed of point W on the cord at t = 0 is 0.94 m s–1. With the cord at its original tension, the frequency of oscillation is now doubled to 10 Hz.

The amplitude is kept at 0.030 m. Calculate the new speed of point W at t = 0. Explain your reasoning.

Did this page help you?