Airdrie Academy Physics Department
Intermediate 2
Waves and Optics Homework 1
1. The sound from a canon takes 2.6 seconds to travel a distance 884 metres.
Calculate the speed of the sound.
(2)
2. How long does it take a sound to travel 0.8 km at 340 m/s?
(3)
3. The speed of sound can be measured in the laboratory using the apparatus
shown below.
a)
Copy the diagram and label the apparatus.
(2)
b)
Describe ( in steps ) how the apparatus can be used to measure the
speed of sound.
(2)
c)
The results from one experiment are as follows:
distance measured = 1.70 m
time on electronic timer = 0.005 s
Use these results to calculate the speed of sound.
(2)
4. A boy at a firework display notices that he sees the flash of an exploding
rocket first and then hears the bang a few seconds later.
a)
Explain (using physics) why this happens.
(2)
b)
The boy hears the bang 1.9 s after the flash. Calculate how far away
the rocket was when it exploded.
(2)
Total (15)
Airdrie Academy Physics Department
Intermediate 2
Waves and Optics Homework 2
1. A wave is shown below.
0.8 m
0.6 m
a)
What is the amplitude of the wave?
(1)
b)
What is the wavelength of the wave?
(1)
2. A man is standing at a harbour wall which is 56 metres long watching waves
pass along the wall.
a)
Calculate the wavelength of one wave if four complete waves take up
the length of the wall.
(2)
b)
If ten waves pass a point in 2.5 s calculate the frequency of the waves.
(2)
3. Copy the following table and use the equation wave speed = frequency X
wavelength to complete it.
Wave speed
4 m/s
340 m/s
340 m/s
Frequency
2 Hz
0.25 Hz
10 Hz
1000 Hz
Wavelength
10 m
15 m
0.034 m
(10)
Total = (16)
Airdrie Academy Physics Department
Intermediate 2
Waves and Optics Homework 3
1. A ray box is used to direct a beam of light onto a mirror. Copy and complete
the diagram below to accurately show the path of the reflected ray. Mark on
the diagram the normal, the angle of incidence and the angle of reflection. (3)
What is the relationship between the angle of incidence and the angle of
reflection?
(1)
2. Curved dishes are used to collect the signals from satellites.
(a)
A
(b)
(c)
3. (a)
What name is given to the part of
the satellite dish labelled A?
(1)
Copy and complete the diagram
to show the path of the incoming
signals after they strike the
curved reflector.
(2)
Describe how a satellite can be used by two ground stations to
communicate with each other. Include a diagram in your explanation.
(3)
Copy and complete the diagram below to show the path of a ray of
light through an optical fibre.
(2)
(b)
Light will travel along an optical fibre at 2 X 108 m/s. How long will it
take a signal to travel from one end to the other of a cable which is 20
km long?
(3)
Total = 15
Airdrie Academy Physics Department
Intermediate 2
Waves and Optics Homework 4
1. Two glass shapes are shown below. In each case a single ray of white light is
entering the shape.
(a)
normal
Copy and complete the diagrams to show the path of the rays of light
passing through the shapes.
(4)
normal
Ray of light
(b)
Mark on the first diagram the angle of incidence, the angle of
refraction and the normal.
(3)
2. (a)
Copy and complete the diagrams below to show the path of the rays of
light after passing through the lenses.
(4)
(b)
Identify which lens is a converging lens and which lens is a diverging
lens.
(2)
3. Draw ray diagrams (with a ruler) to show how a converging lens of focal
length 4 cm forms an image of an object which is 6 cm from the centre of the
lens.
(3)
Total =(16)
Airdrie Academy Physics Department
Intermediate 2
Waves and Optics Homework 5
1. Copy and complete the following table.
Power
Focal length
Converging lens 10 cm
Diverging lens 50 cm
+8D
-4D
+ 0.25 D
(10)
2. An elderly man uses a magnifying glass to help him read the newspaper.
(a)
What is the name of the vision defect he suffers from?
(1)
(b)
His granddaughter explains that he is using a convex lens to correct his
vision. Describe a simple experiment she could carry out to find the
focal length of the magnifying glass for him. Include a diagram. (3)
3. An optician measures the strength of a lens in dioptres. For a particular pair of
glasses he is using a lens with a power of – 0.5 D.
(a)
Calculate the focal length of the lens in metres.
(2)
(b)
Would this lens be used to correct long or short sight? Give a reason
for your answer.
(2)
Total = (18)