
Waves Questions Question 1
Considering a transverse wave, explain the following terms 
a) 
crest and trough 
b) 
amplitude 
c) 
frequency 
d) 
wavelength 
e) 
velocity of propagation. 
Question 2
Explain the following terms (using diagrams where necessary): 
a) 
interference 
b) 
diffraction 
c) 
refraction. 
Question 3
Calculate the frequency of 
a) 
red light of wavelength 650nm 
b) 
violet light of wavelength 420nm 
Question
4
What is the wavelength of x rays of frequency
3×10^{18}Hz 
Question
5
What is the wavelength of sound of frequency
440Hz.
The speed of sound in air is about 340ms^{1}. 
Question
6
A transverse wave of frequency
5Hz moves along a spring at a speed of
1ms^{1}. At t = 0 seconds, point p on the spring is at
it’s maximum displacement of +2cm.
Points A, B and C are points further along
the spring (in the direction of motion of the
wave). 

distance
pA
= 0.4m 

distance
pB = 0.5m 

distance
pC = 0.55m 
Find the displacements of points A, B and C
at 
a) 
t = 0 
b) 
t = 0.2s 
c) 
t = 0.25s 
d) 
t = 0.3s 
Question
7
A tube, closed at one end, is found to have a
fundamental frequency of resonance of f_{o}
= 200Hz. The length of the tube is 40cm 
a) 
Calculate the speed of sound in the tube 
b) 
What is the wavelength of the sound at
resonance (frequency, f_{o}).

c) 
What are the frequencies of the next two
harmonics of the same tube? 
Question
8
The diagram below shows a stationary wave on a wire under tension. The frequency of the oscillations is 1200Hz. 

a) 
If the length of the wire is 40cm, calculate the speed of the waves moving along it. 
b) 
What will happen to the speed of waves moving along the wire if 

i) 
the tension is doubled (all other factors remaining the same) 

ii) 
the length is doubled (all other factors remaining the same)? 
Question
9
A tuning fork is
held near the open
end of a pipe which
is closed at the
other end. The fork
is vibrating at 440Hz.
The length of the
air column in the
pipe is varied. The
first resonance is
heard when the
length of the pipe
is 18.75cm.

a) 
What is the next
length at which
resonance will be
heard (with the same
tuning fork)? 
b) 
Calculate the speed
of sound in the
pipe. 
Question
10
a) 
Two pipes are closed at one end and open at the other end. One pipe has a length of 30cm and the other has a length of 30·5cm. The pipes have the same diameter and therefore the same "endcorrection" of 0·5cm. Calculate the beat frequency which would be heard if both the pipes are caused to resonate at 

i) 
their fundamental frequency (first harmonic) 

ii) 
their first overtone (second harmonic). (Assume the speed of sound is 330ms^{1}) 
b) 
Explain why beats would not be heard if two pipes having lengths of 30cm and 60cm were sounded together. 
Question
11
A transverse sinusoidal wave is represented by the following equation 
y = 0·2sin(20t  0·1x) 
Assuming that the units of the quantities in the equation are metres and seconds, find 
a) 
the amplitude of the wave 
b) 
the wavelength 
c) 
the time period 
d) 
the velocity of propagation (state the direction of propagation) 
e) 
the average transverse speed of a particle in the medium through which the wave is moving. 

