Name : ______________________________
Topic 4 Oscillations and Waves Review Questions 2
1.
This question is about simple harmonic motion and waves.
(a)
A particle of mass m that is attached to a light spring is executing simple
harmonic motion in a horizontal direction.
State the condition relating to the net force acting on the particle that is
necessary for it to execute simple harmonic motion.
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(2)
(b)
The graph shows how the kinetic energy EK of the particle in (a) varies with
the displacement x of the particle from equilibrium.
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(i)
Using the axes above, sketch a graph to show how the potential energy
of the particle varies with the displacement x.
(2)
(ii)
The mass of the particle is 0.30 kg. Use data from the graph and the
formula below to show that the frequency f of oscillation of the particle
is 2.0 Hz.
E K max 
1 2 2 2
4 π mf x 0
2
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(4)
(c)
The particles of a medium M1 through which a transverse wave is travelling,
oscillate with the same frequency and amplitude as that of the particle in (b).
(i)
Describe, with reference to the propagation of energy through the
medium, what is meant by a transverse wave.
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(2)
(ii)
The speed of the wave is 0.80 m s–1. Calculate the wavelength of the
wave.
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(d)
The diagram shows wavefronts of the waves in (c) incident on a boundary XY
between medium M1 and another medium M2.
The angle between the normal, and the direction of travel of the wavefronts is
30°.
(i)
The speed of the wave in M1 is 0.80 m s–1. The speed of the waves in
M2 is 1.2 m s–1.
Calculate the angle between the direction of travel of the wavefronts in
M2 and the normal.
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(3)
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(ii)
2.
On the diagram, sketch the wavefronts in M2.
This question is about the simple pendulum.
(a)
A pendulum consists of a bob suspended by a light inextensible string from a
rigid support. The pendulum bob is moved to one side and then released. The
sketch graph shows how the displacement of the pendulum bob undergoing
simple harmonic motion varies with time over one time period.
On the sketch graph above,
(i)
label with the letter A a point at which the acceleration of the pendulum
bob is a maximum.
(1)
(ii)
label with the letter V a point at which the speed of the pendulum bob is
a maximum.
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(b)
The point of suspension of the pendulum bob is moved from side to side with
a small amplitude and at a variable driving frequency f.
For each value of the driving frequency a steady constant amplitude A is
reached. The oscillations of the pendulum bob are lightly damped.
(i)
On the axes below, sketch a graph to show the variation of A with f.
(2)
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(ii)
Explain, with reference to the graph in (d)(i), what is meant by
resonance.
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