32. (a) An
early type of echo sounder for a boat produces a sound of frequency 2000 Hz.
wavelength of this sound in water is 0.75 m.
What is the speed of the sound in water? Give the unit.
sound is heard by the operator as a brief ‘ping’.
The speed of sound in air is 330 m/s.
What is the wavelength of the sound in air? Give the unit.
echo sounders use higher frequencies than the early type.
Complete the sentence below to describe how the wavelength produced by a
modern echo sounder compares with that produced by the early type.
The wavelength produced by a modern echo sounder is
The diagram shows a wave in a ‘slinky’ spring.
frequency of the waves is 5 pulses per second and the wavelength is 80 cm.
is the wave speed? Give the unit.
33. A writer of science fiction likes to make her stories as
realistic as possible. In her
latest book there is a group of space travellers who discover a star in a
distant part of the galaxy. The
travellers are excited to find a planet very similar to Earth orbiting this
star. They call the planet Delta.
The table compares data about Delta and the Earth.
Most of the figures are relative.
her story, how should the writer compare conditions on Delta with those on
Earth? Tick the correct box in each case.
length of year
length of day
of the planet
(b) One of
the space travellers lands on planet Delta.
With her space suit, she has a mass of 100 kg.
What is her weight on planet Delta? Give the unit.
inclination of the axis of rotation to the axis of orbit is different for Delta
and Earth. In the story, the
travellers spend a year on Delta. Describe
two differences between Delta and Earth that the travellers would find,
apart from their weight.
34. (a) Satellites
orbiting the Earth appear as points of light in the night sky. They look similar
to stars. An astronomer sees a point of light in the night sky.
can she tell that the point of light is a satellite in a low orbit and not a
looks through a telescope and sees another point of light which is a satellite
in a geostationary orbit. How can she tell that this satellite is in a
Hubble Space Telescope is a telescope used to observe the planets and stars. It
is in a satellite orbiting close to the Earth.
one reason why a telescope in orbit gives clear pictures.
(ii) Give one
disadvantage of an astronomical telescope in orbit round the Earth.
(c) In 1994,
astronauts visited The Hubble Space Telescope to repair it. Astronauts have to
train themselves to move objects in a controlled way in space.
Name a pair of antagonistic muscles which has to be controlled.
35. The diagram shows a magnetic lock for a door. It consists
of both a strong permanent magnet
and an electromagnet. It is fitted into the door frame. An iron plate is
attached to the door.
the diagram the switch is open. Explain why the door cannot be opened.
(b) When the
switch is closed the door may be opened. Explain why the door may now be opened.
burglar tries to get in by cutting the wires to the battery. Explain why the
door still cannot be opened.
(d) When the
wires are repaired, the battery is accidentally connected the other way round.
Explain why the door cannot now be opened.
magnetic lock is shown below. It does not have a permanent magnet in it.
Explain how this kind of lock works and why it is not as secure as the
one shown at the beginning of the question.
The graph shows the
results of a test in which a car accelerates to its maximum speed.
Describe how the acceleration of the car changes after the car has
started to move.
does the resultant force on the car change?
The car has a mass of 1000 kg and the maximum forward force on the car,
produced by the engine, is 4000 N.
It is claimed that the car will accelerate from 0 to 24 m/s in 6 seconds.
calculations, with the correct units, to show that the claim is false.
37. (a) An
electrical current is a flow of charge. The
diagram shows a circuit containing six identical bulbs.
In which part of the circuit, A, B, C, D or E, is there:
greatest flow of charge?
(ii) the least flow of charge?
Sulphur is an electrical insulator, but it can be made to conduct
electricity if a very bright light shines on it.
A slab of sulphur is rubbed with a piece of woollen cloth.
Explain how this gives the sulphur a negative electrical charge.
(ii) A very
bright light shines onto a small circular area in the centre of the charged slab
of sulphur. The pattern of charge
on the sulphur alters. The
simplified diagram represents the new pattern of charge.
Explain why the pattern alters in this way.
38. Digital information can be stored on magnetic recording tape in
several different ways. One way is
shown in the diagram below.
The recording head produces a magnetic field.
The magnetic particles in the section of tape under the recording head
line up with the field.
As the tape moves past the recording head, different sections of the tape
become magnetised. The direction of the current is changed at regular intervals.
How would the pattern on the tape be different if the tape were moved
past the recording head more quickly?
direction of the current is changed at regular intervals. The tape is moved past
the recording head at a steady speed.
The gap between the poles of the recording head is made much bigger.
Suggest two effects this might have on the pattern on the tape.
The diagram shows the
Earth’s orbit. The Earth is shown in two positions six months apart. In one of
the positions it is midsummer in Britain, and in the other positions it is
Estimate what time of the day it is in Britain when the Earth is in
position B, and explain your answer.
The Earth has rotated exactly 183 times on its axis as it moved
between the two positions shown.
Explain how you can tell from the diagram that the Earth has rotated a
whole number of times.
Explain how you can tell from the diagram that the time of day in Britain
is different in the two positions.
While the Earth has rotated exactly 183 times, only 182.5 days have
Calculate the exact time taken for each rotation of the Earth on its axis.
The Moon orbits the Earth approximately once each month. However, only
one face of the Moon is ever visible from the Earth.
Explain why we always see the same face of the Moon.
Suggest how long in Earth days the period from sunrise to sunrise will be
at a point on the Moon’s surface.
diagram shows rays of light coming from a point source, reflecting in a plane
mirror, and entering a person's eye. The person sees an image of the light
source at a point behind the mirror.
On the diagram, draw construction lines to find the position where the
image appears. Label the image I.
(b) (i) The person moves further away from the
How does this affect the position of the image relative to the mirror?
The point source of light is moved closer to the mirror, How does this
affect the position of the image?
diagram shows two rays of light coming from a small fish in some water. The rays
enter a person's eye.
The person sees an image of the fish under the water.
On the diagram, draw construction lines to find the position of the image.
Label the image I.
In some parts of the world, people catch fish using spears.
When they see the image of a fish in the water, where should they aim?
The simplified diagram shows
a device which protects people from being electrocuted when using power tools
such as hedge cutters. The wire in one part of the circuit is shown darker to
make the circuit clearer.
the armature is attracted towards the soft iron core, the contacts are pushed
apart and break the circuit.
The power tool, coil A and coil B are all in the same series circuit.
Coils A and B are wound in opposite directions.
current in the coils has no magnetic effect on the armature. Explain why.
A gardener accidentally cuts the wire at point X. Current from the power
supply starts to flow through the gardener to earth.
effect will this have on the armature? Explain your answer.