Download Orbits - GCSE Science Revision

OCR GCSE
Physics
Homework P5a Foundation
Orbits
1
(a) Explain what you understand by the word ‘satellite’.
(b) What is the difference between an artificial satellite and a natural satellite?
(c) Name one natural satellite that orbits the Earth and one artificial satellite.
2
What is the name given to the force acting on any object moving in a circular path and
in which direction must this force act?
3
What force keeps the Moon in orbit around the Earth and the Earth in orbit around the
Sun?
4
The space shuttle is used to carry communication satellites into orbit.
(a) Explain how both the space shuttle and the satellite remain in orbit around the
Earth.
(b) If the space shuttle moved to a higher orbit what would happen to the time period of
the shuttle around the Earth?
5
There are many different types of orbit that an artificial satellite can follow but the two
main types are (i) geostationary orbits and (ii) polar orbits.
(a) What are the main differences between these two types of orbit?
(b) Why are geostationary orbits more useful for telecommunication purposes than
polar orbits?
(c) Make two columns, one labelled ‘Geostationary orbit’ and the other labelled ‘Polar
orbit’ and under these headings list as many uses of satellites in these orbits as you can.
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OCR GCSE
Physics
Homework P5a Higher
Orbits
1
What force keeps the Moon in orbit around the Earth and the Earth in orbit around the
Sun?
2
The force of gravity acts between all masses in the universe:
(a) Write down three things that determine the size of the force of gravity between
two objects.
(b) What happens to the size of this force if the distance between the bodies is doubled?
3
Sketch the path of a comet around the Sun and show, with arrows, its direction of
motion. On your sketch mark the following points: (a) where the comet is moving
fastest and where it is moving slowest, (b) where the gravitational force is increasing
and where it is decreasing.
4
The space shuttle is used to carry communication satellites into orbit.
(a) Explain how both the space shuttle and the satellite remain in orbit around the
Earth.
(b) State and explain what happens to the size of the gravitational force on the space
shuttle when the satellite is released.
(c) If the space shuttle moved to a higher orbit what would happen to the size of this
force and what would happen to the time period of the shuttle around the Earth?
5
There are many different types of orbit that an artificial satellite can follow but the two
main types are (i) geostationary orbits and (ii) polar orbits.
(a) Explain the differences between these two types of orbit.
(b) Why are geostationary orbits more useful for telecommunication purposes than
polar orbits?
(c) Make two columns, one labelled ‘Geostationary orbit’ and the other labelled
‘Polar orbit’, and under these headings list as many uses of satellites in these orbits as
you can.
(d) What is the height of a geostationary orbit?
(e) Why do satellites with lower orbits travel faster?
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OCR GCSE
Physics
Homework P5b Foundation
Vectors and equations of motion
1
Calculate the relative speed of the two cars in the diagrams below
5 m/s
3 m/s
5 m/s
3 m/s
Example A
Example B
2
Explain why speed is a scalar quantity and velocity is a vector quantity.
3
Calculate the vector sum of the following:
(a) 5 N
4
3N
(b) 20 m/s
60m/s
(c) 100 N
50 N
John drops his ball from a cliff by the sea. If he hears the splash four seconds later how
fast will the ball be travelling as it hits the water? (Assume acceleration due to gravity
is 10 m/s2.)
5
A motorcycle travelling at 10 m/s overtakes a car. It takes two seconds to overtake and
is travelling at 14 m/s when completed. How much distance was covered whilst
overtaking?
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OCR GCSE
Physics
Homework P5b Higher
Vectors and equations of motion
1
Calculate the resultant velocity of the aeroplane below
260 m/s
Crosswind 50 m/s
2
Explain why speed is a scalar quantity and velocity is a vector quantity.
3
Calculate the vector sum of the following:
(a) 5 N
3N
(b) 20 m/s
60m/s
(c) 100 N
4
50 N
A motorcycle travelling at 10 m/s overtakes a car. It takes two seconds to overtake and
is travelling at 14 m/s when completed. How much distance was covered whilst
overtaking?
5
A plane touches down on the runway at 30 m/s and decelerates at 1.5 m/s2 until it stops.
How long must the runway be?
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OCR GCSE
Physics
Homework P5c Foundation
Projectiles
Remember that when an object falls under gravity:
(i) it always has a vertical acceleration of 10 m/s2
(ii) its horizontal velocity remains constant.
1
Draw the path of a stone being thrown horizontally from the top of a tall cliff.
2
What is the name given to the shape of the path in the first question?
3
Make a list of at least ten objects that show projectile motion.
4
If air resistance is ignored, what is the only force acting on an object when it is thrown?
5
Why is there no change to the horizontal velocity of a ball that is thrown from the edge
of a high cliff?
6
Why does the vertical velocity of a falling object change?
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OCR GCSE
Physics
Homework P5c Higher
Projectiles
Remember that when an object falls under gravity:
(i) it always has a vertical acceleration of 10 m/s2
(ii) its horizontal velocity remains constant
(iii) the time taken to fall vertically and to move horizontally is always the same
(iv) velocity is a vector quantity and therefore the resultant of the vertical and horizontal
velocities can be found.
1
If air resistance is ignored, what is the only force acting on an object when it is thrown?
2
Why is there no change to the horizontal velocity of a ball that is thrown from the edge
of a high cliff?
3
Why does the vertical velocity of a falling object change?
4
A stone is dropped down a deep well. It takes 4 seconds to reach the bottom. How deep
is the well?
5
A ball is thrown horizontally from the top of a vertical cliff. The cliff is 50 m high and
the ball lands 60 m from the bottom of the cliff.
(a) How long does it take for the ball to reach the bottom of the cliff?
(b) What is the horizontal speed of the ball?
(c) What is the vertical speed of the ball as it lands?
6
A scientist wants to find out how fast he can throw a ball. He throws the ball
horizontally from a height of 2 m and it lands 20 m away from where he is standing.
Calculate the original velocity of the ball.
7
If a boy throws a stone and it hits the Earth with a horizontal velocity of 7 m/s and a
vertical velocity of 10 m/s, calculate its resultant velocity and the angle at which it hits
the Earth.
8
A tennis ball is hit horizontally from the top of a high building. It takes 4 seconds to
reach the ground and it lands 80 m from the building.
(a) What is the height of the building?
(b) At what vertical velocity does the ball hit the ground?
(c) What is its horizontal velocity?
(d) What is its resultant velocity and at what angle does it hit the ground?
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OCR GCSE
Physics
Homework P5d Foundation
Force and momentum
1
If a girl sits on a chair then she exerts a force downwards on the chair and the chair
exerts an equal and opposite force upwards on her. Her force is known as the ACTION
force and the chair’s force is known as the REACTION force. Also the chair legs ACT
downwards on the ground and the ground REACTS upwards on the chair legs.
Sketch the following diagrams and draw on as many ACTION and REACTION forces
as possible:
(a)
(b)
beam
10 kg
(c)
2
(d)
Collisions are essential in many sports and not just one footballer colliding with
another! Explain a situation in which a collision occurring in a sport is useful.
3
Two cars are in a head-on collision. Explain the forces acting on each car that bring
them to a stop.
4
Write a paragraph about car safety features and, using the ideas about momentum, how
they reduce injuries in collisions between vehicles.
5
Sporting injuries are often caused by very rapid acceleration (or deceleration) of the
body. Try to explain why.
6
What two things does the momentum of a body depend upon and what happens if either
is increased?
7
The driver of an 800 kg car travelling at 60 m/s applies her brakes and reduces her
velocity to 20 m/s. The braking takes place over a time of 4 s. Calculate:
(a) the car’s original momentum.
(b) the car’s final momentum.
(c) Why is this braking much safer than when a car is suddenly stopped in an accident?
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OCR GCSE
Physics
Homework P5d Higher
Force and momentum
1
If a girl sits on a chair then she exerts a force downwards on the chair and the chair
exerts an equal and opposite force upwards on her. Her force is known as the ACTION
force and the chair’s force is known as the REACTION force. Also the chair legs ACT
downwards on the ground and the ground REACTS upwards on the chair legs.
Sketch the following diagrams and draw on as many ACTION and REACTION forces
as possible:
(a)
(b)
beam
10 kg
(c)
2
(d)
Write a paragraph about car safety features and, using the ideas about momentum, how
they reduce injuries in collisions between vehicles.
3
Sporting injuries are often caused by very rapid acceleration (or deceleration) of the
body. Try to explain why.
4
The driver of a 800 kg car travelling at 60 m/s applies her brakes and reduces her
velocity to 20 m/s. The braking takes place over a time of 4 s. Calculate:
(a) the car’s original momentum.
(b) the car’s final momentum.
(c) the braking force required.
5
Before
After
4 m/s
2 m/s
5 kg
3 kg
5 kg
3 kg
? m/s
The diagram shows two trolleys moving along a smooth track and colliding. On
collision they join together and move on. Using the figures shown in the diagram,
calculate the final velocity of the trolleys.
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OCR GCSE
Physics
6
Homework P5d Higher
A stationary tank of mass 10 000 kg fires a 250 kg shell at a velocity of 200 m/s.
Calculate the recoil velocity of the tank.
7
Using ideas about conservation of momentum, explain how a large rocket can be
propelled forward by expelling hot gases from the rear of the rocket.
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OCR GCSE
Physics
Homework P5e Foundation
Satellite communication
1
A radio wave is being transmitted in the diagram below:
hill
(a) Sketch the diagram in your book show what happens as the waves pass the hill.
(b) What is this effect called?
(c) What happens to the waves when they reach the Earth’s upper atmosphere?
2
(a) What frequencies of waves a reflected by the ionosphere.
(b) Explain why the strength of radio waves above 30 GHz is reduced as they travel
long distances.
3
Explain in detail how microwave communications are transmitted from one part of the
globe to another. A labelled diagram may help.
4
Compare radio waves and microwaves, how they are similar and what are the
differences between them?
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OCR GCSE
Physics
Homework P5e Higher
Satellite communication
1
What frequencies of waves are reflected by the ionosphere, explain why the strength of
radio waves above 30 GHz is reduced as they travel long distances.
2
Explain in detail how microwave communications are transmitted from one part of the
globe to another. A labelled diagram may help.
3
Explain why radio waves are more suitable for broadcasting than microwaves. You
should describe the differences between them and why these differences help radio
waves travel long distances around the globe.
4
Radio waves carry signals by a process called amplitude modulation. With the aid of a
diagram explain how this process enables sound to be carried.
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OCR GCSE
Physics
Homework P5f Foundation
Interference
1
What happens when two water waves overlap? Explain your answer.
2
If we stand just to the side of an open door we can hear a person speaking in a room but we
cannot see the person. We normally explain this by saying the sound diffracts as it goes
through the door but light travels in a straight lines. Describe how we can make light
diffract (or bend) and why it will not show this effect when travelling through the door.
3
A salesman for tinted front windscreens for customised cars states that the windscreens
he sells are not just tinted they are also polarised and that these windscreens only let
half the light in.
(a) What test could a customer carry out to see if the windscreens were polarised?
(b) Explain polarisation in terms of light waves.
(c) How can you plane polarise light?
4
Two loudspeakers can be set up as shown below. They both play exactly the same note.
loudspeaker 2
loudspeaker 1
1m
Line of students
When students stand in line a few metres in front of the loudspeakers some may hear a loud
note whilst others hear silence.
In terms of reinforcement and cancellation of waves, explain this variation in the
loudness of the note.
5
(a) National radio is broadcast by a series of neighbouring transmission aerials that
cover the whole country. Why do neighbouring aerials broadcast on slightly different
frequencies?
(b) Satellites receive microwave communication at a certain frequency but retransmit it
at a slightly different frequency. Why is there this difference in frequency?
6
In 1802, an English scientist called Thomas Young was the first person to show that
light, after passing through two very narrow slits, caused a pattern of dark and bright
bands (called fringes). Explain why this is often described as the first proof that light is
a wave and not made of particles.
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OCR GCSE
Physics
Homework P5f Higher
Interference
1
A salesman for tinted front windscreens for customised cars states that the windscreens
he sells are not just tinted they are also polarised and that these windscreens only let
half the light in.
(a) What test could a customer carry out to see if the windscreens were polarised?
(b) Explain polarisation in terms of light waves.
(c) How you can plane polarise light?
2 Two loudspeakers can be set up as shown below. They both play exactly the same note.
loudspeaker 2
loudspeaker 1
1m
Line of students
When students stand in line a few metres in front of the loudspeakers some may hear a loud
note whilst others hear silence.
In terms of constructive and destructive interference and the length of path from the
loudspeakers to each student, explain this variation in loudness of the note.
3
(a) National radio is broadcast by a series of neighbouring transmission aerials that
cover the whole country. Why do neighbouring aerials broadcast on slightly different
frequencies?
(b) Satellites receive microwave communication at a certain frequency but retransmit it
at a slightly different frequency. Why is there this difference in frequency?
4
In 1802, an English scientist called Thomas Young was the first person to show that
light, after passing through two very narrow slits, caused a pattern of dark and bright
bands (called fringes). Explain why this is often described as the first proof that light is
a wave and not made of particles.
13 of 40
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OCR GCSE
Physics
Homework P5g Foundation
Refraction of light
1
Complete the following sentences using the words given:
more
red
totally internally reflected
endoscopes
refraction
fibre
blue
bends
speed
dispersed
critical
(a) When light travels from air into glass it _________ towards the normal. This
process is called __________ and is due to a change in __________ of the light.
(b) White light is made up of __________ than one colour and when these colours
travel through glass they are ____________, with __________ light being deviated
more than _______ light.
(c) If light is travelling in glass and it strikes the surface at an angle greater than the
________ angle then it will be __________ ____________ _____________. Different
materials have different ___________ angles. This effect is used in __________ optics
and one use of this is in ___________.
2
When light travels into a glass block it refracts.
(a) Draw a diagram to represent the light travelling through a glass block.
(b) What happens to the speed of the light as it travels into the glass?
(c) Which way does the light bend when it slows down?
(d) What is the property of the material that controls the amount of bending?
3
(a) Draw a diagram to show white light travelling through a 60º prism.
(b) Why does the light split up into different colours?
(c) What is this process called?
4
Light can be totally internally reflected (TIR).
(a) Draw three diagrams to show light passing from glass towards air when it is
(i) incident at an angle less than the critical angle, (ii) incident at an angle equal to the
critical angle and (iii) incident at an angle greater than the critical angle.
(b) Draw a diagram of a ray of light passing through an optical fibre.
(c) Write down two things about light that is undergoing TIR.
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OCR GCSE
Physics
Homework P5g Higher
Refraction of light
1
When light travels into a glass block it refracts.
(a) Draw a diagram to represent the light travelling through a glass block.
(b) What happens to the speed of the light as it travels into the glass?
(c) Which way does the light bend when it slows down?
(d) What is the property of the material that controls the amount of bending?
2
(a) Draw a diagram to show white light travelling through a 60º prism.
(b) Why does the light split up into different colours?
(c) What is this process called?
3
Light can be totally internally reflected (TIR).
(a) Draw three diagrams to show light passing from glass towards air when it is
(i) incident at an angle less than the critical angle, (ii) incident at an angle equal to the
critical angle, (iii) incident at an angle greater than the critical angle.
(b) Draw a diagram of a ray of light passing through an optical fibre.
(c) Write down two things about light that is undergoing TIR.
The refractive index of a material probably has more equations than any other physical
property that you study at GCSE, all of the following equations apply:
Refractive index = speed of light in a vacuum
Speed of light in medium
n = sin i,
sin r
sin c = nr
ni
Using these equations to do the following calculations:
4
If the speed of light in a vacuum is 3 x 108 m/s and in an unknown liquid 1.5 x 108 m/s,
calculate the refractive index of the liquid.
5
If the refractive index of glass is 1.5 and light is incident upon it at 30º, calculate the
angle of refraction. You will have to change the subject of the equation.
6
If an optical fibre is made of glass (refractive index = 1.5) and the fibre is in air
(refractive index = 1), what is the critical angle inside the fibre? What happens to the
critical angle when the fibre is immersed in water (refractive index = 1.3)?
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OCR GCSE
Physics
Homework P5h Foundation
Optics
1
The diagram below shows rays of light entering a thin and a thick convex lens. Draw
the paths of the light after the rays have entered the lenses, marking the focal length on
each diagram.
Lens A
Lens B
2
What do we mean by the term converging?
3
Projectors and magnifying glasses produce images that are larger than the original
objects. For both devices to work the object must be a precise distance from the lens.
What is the relationship between object and lens in:
(a) a projector?
(b) a magnifying glass?
(Hint: it has something to do with the focal length of the lens.)
4
A film camera needs to focus on near and far objects. We do this by changing the
thickness of the lens in our eye. Cameras cannot do this so how does it change focus?
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OCR GCSE
Physics
Homework P5h Higher
Optics
1
Projectors and magnifying glasses produce images that are larger than the original
objects. For both devices to work the object must be a precise distance from the lens.
What is the relationship between object and lens in:
(a) a projector?
(b) a magnifying glass?
(Hint: it has something to do with the focal length of the lens.)
2
A film camera needs to focus on near and far objects. We do this by changing the
thickness of the lens in our eye. Cameras cannot do this so how does it change focus a
clear image?
3
An object with a height of 1.5 cm is placed 4 cm from a lens with a focal length of
2.5 cm.
(a) Draw a diagram to show how the image is formed.
(b) How far from the lens is the image and what is its height?
(c) How can you tell the image will be magnified before you draw the diagram?
4
A classroom overhead projector magnifies transparencies by five times. If a
transparency is 10 cm by 5 cm, what size is the image?
8
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OCR GCSE
Physics
5
P5a Orbits
Foundation
1
2
3
4
5
(a) a satellite is an object that orbits a
larger object in space
[1]
(b) an artificial satellite has been man
made whereas a natural satellite has been
formed by nature
[1]
(c) the Moon, any man-made satellite
e.g. Metostat
[2]
centripetal force, it acts towards the
centre of the circle.
[2]
force due to gravity
[1]
but a better answer would be:
the gravitational force provides the
centripetal force
[2]
(a) the gravitational force, provides the
centripetal force, needed to keep the
shuttle and satellite in a circular orbit
[3]
(b) the time period will get longer
[1]
(a) answer same as 5(a) higher
[any 5]
(b) answer same as 5(b) higher
[3]
(c) answer same as 5(c) higher
[any 6]
Higher
1
2
3
4
Homework Mark Scheme
P5a&P5b Foundation & Higher
force due to gravity
but a better answer would be:
the gravitational force provides the
centripetal force
(a) Size of each mass, distance between
the masses.
(b) It is a quarter as strong.
Sketch of an ellipse with the Sun at one
focus, arrows moving towards and away
from Sun
(a) point nearest to Sun labelled fastest,
point furthest from Sun labelled slowest
(b) somewhere on part of path moving
away from the Sun labelled gravitational
force decreasing
(a) the gravitational force, provides the
centripetal force, to keep the shuttle and
satellite in a circular orbit.
(b) mass gets less, therefore the
gravitational force gets less
(c) gravity gets less because of
greater distance. Time period gets
longer
[1]
(a) answer should include: geostationary
orbits are: higher, always above the same
point on the Earth’s surface (NOT
stationary above Earth), time period is 24
hours, always above the equator
polar orbits are much lower, gradually
pass over all the Earth, time period only
a few hours, goes over both poles.
[any 5]
(b) transmitters and receivers only need
point to one position in the sky, possible
to transmit information between two
points on the Earth 24 hours a day, only
require three satellites to cover the whole
of the Earth.
[3]
(c) Geostationary
Polar
communications
weather
e.g. TV, radio, telephone military
weather forecasting
e.g. spying
GPS
Earth watch
e.g. land use, ice
cap etc
[any 6]
(d) 35 800 km
[1]
(e) Lower orbits mean the gravitational
force is greater, therefore the
satellite has to travel faster.
[2]
P5b Vectors and
equations of motion
Foundation
[2]
[3]
[1]
[1]
[1]
[1]
1 (a) 2 m/s (b) 8m/s
2 speed only has a size
velocity has a size and a direction
3 (a) 8 N to the right
(b) 80 m/s to the left
(c) 50 N to the right
4 40 m/s
5 24 m
[2], [1]
[1]
[1]
[2]
[2]
[2]
[4]
[4]
Higher
[1]
[3]
[2]
[2]
1 264.8 m/s
bearing 190.9º/angle 10.9º
2 speed only has a size
velocity has a size and a direction
3 (a) 8 N to the right
(b) 80 m/s to the left
(c) 50 N to the right
4 24 m
5 300 m
[2]
[2]
[1]
[1]
[2]
[2]
[2]
[4]
[4]
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OCR GCSE
Physics
Homework Mark Scheme
P5c&P5d Foundation & Higher
P5c Projectiles
Foundation
1
2
3
4
5
6
diagram showing a parabolic path
parabola
any list of 10, e.g. golf balls, javelin, etc.
gravity
because there are no horizontal forces
because the force of gravity acts
vertically downwards
[1]
[1]
[5]
[1]
[1]
[1]
Higher
1
2
3
4
5
6
7
8
3
4
gravity
there is no horizontal force
because gravity only acts downwards
80 m
(a) 3.2 s
(b) 18.75 m/s
(c) 32 m
time to fall = 0.63 s
horizontal velocity = 31.6 m/s
resultant velocity = 12.2 m/s
angle = 55°
(a) 80 m
(b) 40 m/s
(c) 20 m/s
(d) 44.7 m/s at an angle of 63°
[1]
[1]
[1]
[2]
[2]
[2]
[2]
[1]
[2]
[2]
[2]
[2]
[2]
[2]
[4]
P5d Force and
momentum
Foundation
1
2
(a) action of man on scales, reaction of
scales on man; it will be a bonus if also
action of scales on floor and reaction of
floor on scales
(b) two sets of action and reaction pairs,
one pair between beam and rope and one
pair between rope and weight.
(c) two sets of action and reaction, one at
each end of the rope between the boy and
5
6
7
[2]
[2]
[2]
[2]
[1]
[4]
[2]
[2]
[1]
[1]
[2]
Higher
1
2
3
4
5
6
7
[2]
the rope. Some may draw the action and
reaction between the boys and the
ground
(d) action of gases coming out of the
back of the rocket and the reaction of the
these gases on the rocket
explanation of any type of bat and ball
collision, e.g. cricket bat and ball. The
ball exerts an action on the bat and the
bat exerts an equal and opposite reaction
on the ball
one car exerts a force on the other car
and the second car exerts an equal and
opposite reaction on the first
mention should be made of seatbelts,
crumple zones and airbags. How each of
these increase the time over which an
accident occurs and this decreases the
acceleration (deceleration) and therefore
reduces the force on the passenger
rapid acceleration must mean a large
force on the body and therefore the risk
of injury
mass and velocity, if either increases
then momentum increases
(a) 48 000 kg m/s
(b) 16 000 kg m/s
(c) longer time period and therefore less
acceleration and less force
same as in Q1 foundation
same as in Q4 foundation
same as in Q5 foundation
(a) 48 000 kg m/s
(b) 16 000 kg m/s
(c) 8000 N
3.25 m/s
5 m/s
gases exert an equal and opposite
reaction on rocket, gases have a large
velocity, therefore have a high change in
momentum backwards, this must be
equal to the change in momentum of
rocket forwards.
[8]
[4]
[2]
[2]
[2]
[2]
[3]
[3]
[4]
19 of 40
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OCR GCSE
Physics
Homework Mark Scheme
P5e&P5f Foundation & Higher
4
P5e Communications
+
radio wave
(carrier wave)
Foundation
1
(a)
[1]
=
3
(b) diffraction
(c) they are reflected
frequencies above 30 GHz
absorbed by gases and rain, scattered by
dust
they are transmitted to a satellite
that retransmits it back to Earth
[4]
[1]
[1]
Foundation
1
[2]
[1]
[1]
2
3
2
1
4
transmitter
5
4
they are both electromagnetic waves,
both transverse
microwaves higher frequency, radio
waves diffract in atmosphere, radio
waves reflected off ionosphere
[2]
6
[2]
Higher
1 Frequencies above 30 GHz
absorbed by gases and rain
scattered by dust
2 They are transmitted to a satellite
which retransmits it back to Earth
3 Radio waves are diffracted more
because of longer wavelength
[1]
[2]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
P5f Interference
satellite
receiver
amplitude
modulated
radio wave
sound wave converted to electrical signal
is added to an EM wave called the carrier,
receiver has a circuit to recover signal
hill
2
sound wave
(changed into an
electrical wave)
they interfere, if trough meets a trough or
a crest meets a crest then a large wave is
produced, but if a trough meets a crest
then no wave motion is observed
[3]
we need a very narrow slit, about the same
size as the wavelength of light, width of
door is too great
[3]
(a) rotate a sheet of polarised glass/plastic
in front of windscreen, and it should go
from allowing light through to no light
[2]
(a) transverse vibrations, in all directions
[2]
(b) place one sheet of polariser in the
path of the light.
[1]
they interfere, if trough meets a trough or
a crest meets a crest then a loud sound is
heard, but if a trough meets a crest then
no sound (silence) is observed
[3]
(a) if the same frequency they could
interfere and produce no signal
[2]
(b) if the same then the incoming signal could
interfere with the transmitted signal
[2]
only waves cause interference
[1]
Higher
1
2
3
5
same as Q3 in foundation
[5]
loud note produced by troughs arriving with
troughs and with crests arriving with crests,
in phase, constructive interference, path
difference a whole number of waves
[4]
silence produced by trough arriving with a crest,
out of phase, destructive interference, path
difference an odd number of half waves
[4]
same as Q5 foundation
[4]
same as Q6 foundation
[1]
20 of 40
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OCR GCSE
Physics
Homework Mark Scheme
P5g&P5h Foundation & Higher
(b)
P5g Refraction
Foundation
Strictly speaking the phrase ‘total
internal reflection’ does not appear
in the foundation specification and
so questions 1(c) and 4 could be
answered without reference to TIR.
1
2
optical fibre
(c) must be travelling in the more dense
medium, must be incident at an angle
greater than the critical angle
(a) bends, refraction, speed
(b) more, dispersed, blue, red
(c) critical, totally internally reflected,
critical, fibre, endoscopes
(a)
angle of incidence
[3]
[3]
[5]
[3]
angle of
refraction
3
[2]
(b) it slows down
(c) towards the normal
(d) the refractive index
(a)
[2]
Higher
1
2
3
4
5
6
same as Q2 foundation
same as Q3 foundation
same as Q4 foundation
n=2
19.5º
when the fibre is in air the critical angle
in the glass 41.8º (sin C = 1/1.5),
when the fibre is in water the critical
angle in the glass increases to 60.1º
(sin C = 1.3/1.5)
[2]
[2]
[4]
[1]
[1]
[1]
[2]
red
white
light
4
blue
(b) each colour travels at a different
speed or has a different refractive index
(c) dispersion
most
(a)
[1]
[1]
[3]
refracted
air
glass
little
reflection
Less than critical angle
air
glass
Equal to critical angle
air
glass
all reflected
Greater than critical angle
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21 of 40
OCR GCSE
Physics
Homework Mark Scheme
P5g&P5h Foundation & Higher
P5h Optics
Foundation
1
lines converging from both lenses
focal length shorter for fatter lens
[2]
[1]
F
F
2 coming together
3 (a) object between f and 2f of lens
(b) object closer than f of lens
4 distance between lens and film changes
[1]
[1]
[1]
[1]
Higher
1
2
3
(a) object between f and 2f of lens
(b) object closer than f of lens
distance between lens and film changes
(a) suitable diagram
[1]
[1]
[1]
[2]
convex
lens
6.7 cm
1.5 cm
2.5 cm
F
image
object
4 cm
2.5 cm
2.5 cm
4
(b) 5.5 cm, 2 cm high
(c) object closer than 2f
50 cm by 25 cm
[2]
[1]
[2]
22 of 40
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This document may have been altered from the original.
OCR GCSE
Physics
Self-assessment quiz
P5a Foundation and Higher
Orbits and satellites
1
Fill in the gaps below using the words from the list:
geostationary
communications
polar
greater
[F/H]
lower
imaging
gravity
The Moon, just like man made satellites, orbits the Earth due to the force of _________ .
The higher a polar satellite’s orbit the _________ the orbital period. A _________
satellite remains in a fixed position above the Earth’s surface. An example of a satellite
that uses a geostationary orbit is one used for _____________.
2
True or false? Put T or F in the boxes
[F/H]
The higher the orbit the faster a satellite travels.
Imaging satellites are in geostationary orbits.
A geostationary satellite orbits the equator in 24 hours.
Gravity provides the centripetal force for orbital motion.
3
There are a number of errors in the following paragraph. Spot them and correct them in
the space below.
[H]
The force of gravity can explain the orbits of planets and their satellites as well as
objects such as comets. As a comet gets closer to the Sun its speed increases as ice
melts and its mass decreases. The orbital period of a satellite (how fast it travels around
the planet) increases with the distance from the surface. Low polar satellites orbit in
many days as the force of gravity is greater closer to the planets. Satellites do not fall to
the Earth because gravity keeps them moving at an approximately circular orbit.
(a) ___________________________________________________________.
(b) ___________________________________________________________.
(c) ___________________________________________________________.
(d) ___________________________________________________________.
23 of 40
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OCR GCSE
Physics
Self-assessment quiz
P5b Foundation and Higher
Vectors and equations of motion
1
Complete the following crossword by filling in the missing words below to find an
acronym for equations of motion.
[F/H]
1
2
3
4
5
2
1
________ can be calculated by multiplying the average velocity by the time.
2
There are four ________ of motion.
3
________ is speed in a given direction.
4
Mass and temperature are ________ quantities.
5
Force and velocity are ________ quantities.
The equations of motion are often known as the ‘suvat’ equations because
s stands for ________ measured in ________________.
u stands for ________________ measured in ________________.
v stands for ________________ measured in ________________________.
a stands for ________________ measured in ________________________
t stands for ________ measured in ________________.
3
Are the following statements true or false? Put T or F in the boxes.
[F/H]
[F]
Speed is a measure of how fast an object is moving.
Direction is important when measuring speed.
If two cars approach each other on a straight road then their relative speed
decreases.
Average speed can be calculated by multiplying the total distance travelled by the
time taken.
In vector quantities direction is important.
4
5
A car starting from rest steadily increases its speed up to 20 m/s in 5 s. How far has it
travelled?
______________
______________
answer = ____
A body with a velocity of 4 m/s has an acceleration of 5 m/s2 for 10 s. What is its final
velocity?
______________
______________
answer = ____
[F/H]
[F/H]
24 of 40
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OCR GCSE
Physics
6
7
8
Self-assessment quiz
P5b Foundation and Higher
A car starting from rest has an acceleration of 4 m/s2. How long does it take to travel a
distance of 200 m?
______________
______________
______________
answer = ____
A body with an initial velocity of 10 m/s has an acceleration of 2 m/s2. What is its
velocity after it has travelled 11 m?
______________
______________
answer = ____
Draw lines between the boxes in the left-hand column and the correct answer in the
right-hand column.
The resultant of two
parallel vectors travelling
in the same direction is …
equal to the difference between the
two vectors and in the direction of
the largest vector.
The resultant of two
vectors at right angles to
each other is ….
VR2 = Va2 + Vb2
The resultant of two
parallel vectors pointing
in opposite directions is ...
equal to the sum of the two vectors
and is in the same direction as the
original vectors.
The resultant of two
vectors at right angle to
each other can be
calculated using the
equation …
equal to the diagonal of the rectangle
drawn to scale using the vectors as
the sides of the rectangle.
[H]
[H]
[H]
25 of 40
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This document may have been altered from the original.
OCR GCSE
Physics
Self-assessment quiz
P5c Foundation and Higher
Motion of falling objects
1
Fill in the gaps using the words from the list
horizontal
constant
accelerating
[F/H]
air resistance
force
increases
When we talk about the velocity of falling objects we ignore _________ . If this is ignored
then the only _________ acting on the object is gravity. The horizontal velocity of falling
objects is _________ and the vertical velocity of the object _________. If the object’s speed
increases we say it is _________. As gravity only acts downwards it has no affect on the
_________ velocity of the object.
2
A boy drops a stone from a bridge over a river and his friend throws a similar stone
horizontally into it at the same time.
[F/H]
Complete these sentences:
(a) We say that the thrown stone has constant horizontal velocity because
___________________________.
(b) Both stones hit the water at the same time ____________________________________
___________________________.
3
The following sentences regarding projectiles have been mixed up. Connect them up so
they make correct statements.
[H]
The resultant velocity of a
projectile
in the horizontal direction.
Near the surface of the Earth
is the vector sum of the
horizontal and vertical velocities.
There is no acceleration
Momentum
1
the gravitational field is uniform.
Fill in the gaps using words from the list. Choose four different words from the list.
force
energy
momentum
movement
acceleration
increase
[F/H]
decrease
If you multiply an object mass and velocity together you calculate a property called
_________. Sporting injuries are often caused by a rapid _________ of parts of the body.
Crumple zones reduce injuries as the _________ of a collision is reduced. This is reduced
because as the zone crumples it _________ the time of the collision.
2
Solve the clues across. The shaded column is a word that is central to this item.
[H]
26 of 40
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OCR GCSE
Physics
Self-assessment quiz
P5d Foundation and Higher
1
2
3
4
5
6
7
8
1
The more of this an object has the more momentum it has.
2
Reducing this in collisions reduces the chance of serious damage to passengers.
3
This zone absorbs the energy during front or rear end collisions.
4
What type of belt stops passengers colliding with hard surfaces on the dash board.
5
This is reduced when air bags are deployed.
6
Reducing this slowly reduces deceleration.
7
Spreading the change in momentum over a longer time does this to the forces in
collisions.
8
All safety features increase this during collisions.
27 of 40
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OCR GCSE
Physics
Self-assessment quiz
P5e Foundation and Higher
Long distance communication
1
Complete the following crossword.
[F/H]
1
2
3
4
5
6
7
8
2
1
These waves are very suitable for broadcasting.
2
Radio waves can be reflected off this part of the atmosphere.
3
This occurs when light hits a mirror or water waves hits a hard surface.
4
This occurs when a wave travels through a narrow gap.
5
Radios require one of these to collect radio signals.
6
When this gets bigger then the amount of diffraction gets less.
7
Satellites use this type of wave for communication.
8
This happens to some electromagnetic waves when they meet dust.
Answer these questions True or false. Put T or F in the boxes.
[F/H]
Radio waves of frequency below 30 MHz can be reflected by the ionosphere.
Radio waves cannot be diffracted around the curve of the Earth.
Radio waves have a longer wavelength than microwaves.
Satellites use radio waves and not microwaves for communication.
3
Explain what is wrong with the following statements:
[H]
(a) Microwaves are sent as thin beams because they have long wavelengths.
______________________________________________________.
(b) Minimum diffraction occurs when the wavelength equals the size of the gap.
______________________________________________________.
(c) In amplitude modulation the radio wave is the signal and the sound wave is the
carrier.
______________________________________________________.
(d) Microwaves diffract more than radio waves because of their longer wavelength.
______________________________________________________.
28 of 40
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OCR GCSE
Physics
Self-assessment quiz
P5f Foundation and Higher
Nature of waves
1
Fill in the gaps using words from the list. Choose four different words from the list.
destructive
larger
interference
cancel
crests
constructive
[F/H]
trough
___________ occurs between waves when they overlap. When the crest of one wave arrives at
a point at the same time as a _________ from another they are out of phase and _________
each other out. This is known as ___________ interference. If two ________ or two troughs
arrive at the same time they are in phase, adding together to form a _______ wave. This is
known as ___________ interference.
2
True or false? Put T or F in the boxes.
[H]
Diffraction patterns are proof that light acts like a stream of particles.
An even number of half wavelengths leads to destructive interference.
Light can be polarised as it is a transverse wave.
Interference patterns are due to light being diffracted.
3
Complete these sentences
[H]
Unpolarised light vibrates in ___________.
After passing through a polarising filter the whole wave is contained in ___________.
A second filter will allow light to pass through if it is ___________________.
The wave is blocked if the second filter is ___________________.
When light reflects off water it is part polarised because _____________________________
______________________.
Polaroid lenses reduce glare because they _______________________________________
such as water.
29 of 40
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This document may have been altered from the original.
OCR GCSE
Physics
Self-assessment quiz
P5g Foundation and Higher
Refraction and TIR
1
Solve the clues across. The shaded column is a scientific word of which a rainbow is
one.
[F/H]
1
2
3
4
5
6
7
8
2
1
This changes when a wave reaches a boundary.
2
This effect produces a rainbow when white light goes through a prism.
3
This happens at a boundary when the incident angle is small.
4
At this angle light travels along the boundary.
5
This is the angle between the normal line and the wave going towards a boundary.
6
The colour that is refracted the least through a prism.
7
The junction between air and plastic is an example of a ___________
8
The scientific name for the stuff a wave is travelling through.
True or false? Put T or F in the boxes.
[F/H]
Refraction occurs at a boundary due to the change in a wave’s frequency.
When a wave’s speed decreases it bends towards the normal.
Waves refract the most when there is a small change in speed.
Dispersion occurs because colours have different wave speeds.
3
Fill in the gaps using words from the list. Choose four different words from the list.
higher
lower
greater
lower
[H]
higher
Total internal reflection can only occur when a ray of light travels from a medium with
a ______ refractive index into a medium with a ______ one. Also the angle of
incidence must be ______ than the critical angle. The ______ the refractive index of a
medium the ______ its critical angle.
30 of 40
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OCR GCSE
Physics
Self-assessment quiz
P5h Foundation and Higher
Lenses
1
Complete the following ray diagram and mark the focal point on the diagram.
2
Complete the following sentences using the words given.
convex
real
converging
focal length
smaller
[F/H]
[F]
centre
(a) A convex lens sometimes known as a ________ lens.
(b) The distance from the ________ of the lens to the focal point is known as the
________________.
(c) A thick lens will have ________ focal length than a thin lens.
(d) Cameras and projectors both use ________ lenses and produce ________ images.
3
Complete the following ray diagram by drawing two rays from the top of the object to
the top of the image.
[H]
object
image
4
A convex lens produces an image 8 cm high of an object that was originally 4 cm high.
Calculate the magnification.
[H]
___
5
How would you adjust a camera lens to produce a focused image on the film?
[F/H]
________________________________________________________
31 of 40
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OCR GCSE
Physics
Self-assessment quiz: answers
P5a Foundation and Higher
Orbits and satellites
1
Fill in the gaps below using the words from the list:
geostationary
communications
polar
greater
[F/H]
lower
imaging
gravity
The Moon, just like man made satellites, orbits the Earth due to the force of gravity.
The higher a polar satellite’s orbit the greater the orbital period. A geostationary
satellite remains in a fixed position above the Earth’s surface. An example of a satellite
that uses a geostationary orbit is one used for communications.
2
True or false? Put T or F in the boxes
The higher the orbit the faster a satellite travels.
Imaging satellites are in geostationary orbits.
A geostationary satellite orbits the equator in 24 hours.
Gravity provides the centripetal force for orbital motion.
3
[F/H]
F
F
T
T
There are a number of errors in the following paragraph. Spot them and correct them in
the space below.
[H]
The force of gravity can explain the orbits of planets and their satellites as well as
objects such as comets. As a comet gets closer to the Sun its speed increases as ice
melts and its mass decreases. The orbital period of a satellite (how fast it travels around
the planet) increases with the distance from the surface. Low polar satellites orbit in
many days as the force of gravity is greater closer to the planets. Satellites do not fall to
the Earth because gravity keeps them moving at an approximately circular orbit.
(a) A comet’s speed increases as the gravitational force increases.
(b) The orbital period is the time taken to orbit.
(c) Low polar satellites orbit in a few hours.
(d) Satellites do not fall as their tangential motion keeps the orbit circular.
32 of 40
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This document may have been altered from the original.
OCR GCSE
Physics
Self-assessment quiz answers
P5b Foundation and Higher
Vectors and equations of motion
1
Complete the following crossword by filling in the missing words below to find an
acronym for equations of motion.
1
2
D
E
C
V
A
E
I
Q
3
4
S
5
2
L
C
S
U
V
A
T
T
A
E
R
O
A
T
L
[F/H]
N
I
O
C
O
C
E
N
I
S
T
Y
R
1
Distance can be calculated by multiplying the average velocity by the time.
2
There are four equations of motion.
3
Velocity is speed in a given direction.
4
Mass and temperature are scalar quantities.
5
Force and velocity are vector quantities.
The equations of motion are often known as the ‘suvat’ equations because
s stands for DISTANCE measured in metres (m).
u stands for ORIGINAL VELOCITY measured in metres per second (m/s).
v stands for FINAL VELOCITY measured in metres per second (m/s).
a stands for ACCELERATION measured in metres per second squared (m/s2)
t stands for TIME measured in seconds (s).
3
Are the following statements true or false? Put T or F in the boxes.
Speed is a measure of how fast an object is moving.
Direction is important when measuring speed.
If two cars approach each other on a straight road then their relative speed
decreases.
Average speed can be calculated by multiplying the total distance travelled by the
time taken.
In vector quantities direction is important.
4
[F/H]
[F]
T
F
F
F
T
A car starting from rest steadily increases its speed up to 20 m/s in 5 s. How far has it
travelled?
[F/H]
s = (u + v)t/2
s = (0 + 20)5/2
answer = 50 m
5
A body with a velocity of 4 m/s has an acceleration of 5 m/s2 for 10 s. What is its final
velocity?
[F/H]
v = u + at
33 of 40
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Physics
Self-assessment quiz answers
P5b Foundation and Higher
v = 4 + 5 x 10
answer = 54 m
6
A car starting from rest has an acceleration of 4 m/s2. How long does it take to travel a
distance of 200 m?
1
[H]
2
s = ut + /2at
200 = 0 + 1/2x4 t2
t2 = 200/2
answer = 10 s
7
A body with an initial velocity of 10 m/s has an acceleration of 2 m/s2. What is its
velocity after it has travelled 11 m?
2
[H]
2
v = u + 2as
v2 = 102 + 2x2x11
answer = 12 m/s
8
Draw lines between the boxes in the left-hand column and the correct answer in the
right-hand column.
The resultant of two
parallel vectors travelling
in the same direction is…
equal to the difference between the
two vectors and in the direction of
the largest vector.
The resultant of two
vectors at right angles to
each other is…
VR2 = Va2 + Vb2
The resultant of two
parallel vectors pointing
in opposite directions is...
equal to the sum of the two vectors
and is in the same direction as the
original vectors.
The resultant of two
vectors at right angle to
each other can be
calculated using the
equation…
equal to the diagonal of the rectangle
drawn to scale using the vectors as
the sides of the rectangle.
[H]
34 of 40
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This document may have been altered from the original.
OCR GCSE
Physics
Self-assessment quiz: answers
P5c Foundation and Higher
Motion of falling objects
1
Fill in the gaps using the words from the list
horizontal
constant
accelerating
[F/H]
air resistance
force
increases
When we talk about the velocity of falling objects we ignore air resistance. If this is
ignored then the only force acting on the object is gravity. The horizontal velocity of falling
objects is constant and the vertical velocity of the object increases. If the object’s speed
increases we say it is accelerating. As gravity only acts downwards it has no affect on the
horizontal velocity of the object.
2
A boy drops a stone from a bridge over a river and his friend throws a similar stone
horizontally into it at the same time.
[F/H]
Complete these sentences:
(a) We say that the thrown stone has constant horizontal velocity because we ignore air
resistance.
(b) Both stones hit the water at the same time because the only force on both stones is
gravity.
3
The following sentences regarding projectiles have been mixed up. Connect them up so
they make correct statements.
[H]
The resultant velocity of a
projectile
in the horizontal direction.
Near the surface of the Earth
is the vector sum of the
horizontal and vertical velocities.
There is no acceleration
the gravitational field is uniform.
35 of 40
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OCR GCSE
Physics
Self-assessment quiz: answers
P5d Foundation and Higher
Momentum
1
Fill in the gaps using words from the list. Choose four different words from the list.
force
energy
momentum
movement
acceleration
increase
[F/H]
decrease
If you multiply an object mass and velocity together you calculate a property called
momentum. Sporting injuries are often caused by a rapid acceleration of parts of the body.
Crumple zones reduce injuries as the force of a collision is reduced. This is reduced
because as the zone crumples it increases the time of the collision.
2
Solve the clues across. The shaded column is a word that is central to this item.
6
V
E
2
3 C R
4
5
L O C
7 R E
8 T
1
F
U
S
I
I
D
I
M
O
M
E
N
T
U
M
A
R
P
A
J
Y
C
E
S
C
L
T
U
S
E
E
E
S
R
[H]
Y
1
The more of this an object has the more momentum it has.
2
Reducing this in collisions reduces the chance of serious damage to passengers.
3
This zone absorbs the energy during front or rear end collisions.
4
What type of belt stops passengers colliding with hard surfaces on the dash board.
5
This is reduced when air bags are deployed.
6
Reducing this slowly reduces deceleration.
7
Spreading the change in momentum over a longer time does this to the forces in
collisions.
8
All safety features increase this during collisions.
36 of 40
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This document may have been altered from the original.
OCR GCSE
Physics
Self-assessment quiz answers
P5e Foundation and Higher
Long distance communication
1
Complete the following crossword.
1
8
2
3
R
[F/H]
A
D
I
O
2
I
O
N
O
S
P
H
E
3
R
E
F
L
E
C
T
I
O
N
4
5
D
I
F
F
R
A
C
T
I
O
A
E
R
I
A
L
6
G
A
P
7
M
I
C
R
O
W
A
V
E
S
S
C
A
T
T
E
R
E
D
R
E
N
1
These waves are very suitable for broadcasting.
2
Radio waves can be reflected off this part of the atmosphere.
3
This occurs when light hits a mirror or water waves hits a hard surface.
4
This occurs when a wave travels through a narrow gap.
5
Radios require one of these to collect radio signals.
6
When this gets bigger then the amount of diffraction gets less.
7
Satellites use this type of wave for communication.
8
This happens to some electromagnetic waves when they meet dust.
Answer these questions True or false. Put T or F in the boxes.
[F/H]
Radio waves of frequency below 30 MHz can be reflected by the ionosphere.
T
Radio waves cannot be diffracted around the curve of the Earth.
F
Radio waves have a longer wavelength than microwaves.
T
Satellites use radio waves and not microwaves for communication.
F
Explain what is wrong with the following statements:
[H]
(a) Microwaves are sent as thin beams because they have long wavelengths.
They have a short wavelength and only diffract a small amount.
(b) Minimum diffraction occurs when the wavelength equals the size of the gap.
Maximum diffraction occurs.
(c) In amplitude modulation the radio wave is the signal and the sound wave is the
carrier.
The radio wave is the carrier and the sound wave is the signal.
(d) Microwaves diffract more than radio waves because of their longer wavelength.
Radio waves have the longest wave and therefore diffract the most.
37 of 40
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This document may have been altered from the original.
OCR GCSE
Physics
Self-assessment quiz: answers
P5f Foundation and Higher
Nature of waves
1
Fill in the gaps using words from the list. Choose four different words from the list.
destructive
larger
interference
cancel
crests
constructive
[F/H]
trough
Interference occurs between waves when they overlap. When the crest of one wave arrives at
a point at the same time as a trough from another they are out of phase and cancel each other
out. This is known as destructive interference. If two crests or two troughs arrive at the same
time they are in phase, adding together to form a larger wave. This is known as constructive
interference.
2
3
True or false? Put T or F in the boxes.
[H]
Diffraction patterns are proof that light acts like a stream of particles.
F
An even number of half wavelengths leads to destructive interference.
F
Light can be polarised as it is a transverse wave.
T
Interference patterns are due to light being diffracted.
T
Complete these sentences
[H]
Unpolarised light vibrates in all directions.
After passing through a polarising filter the whole wave is contained in just one plane.
A second filter will allow light to pass through if it is lined up with the first.
The wave is blocked if the second filter is turned through 90 degrees.
When light reflects off water it is part polarised because more waves are reflected parallel
to the surface.
Polaroid lenses reduce glare because they block reflections from a horizontal surface such
as water.
38 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Physics
Self-assessment quiz: answers
P5g Foundation and Higher
Refraction and TIR
1
Solve the clues across. The shaded column is a scientific word of which a rainbow is
one.
[F/H]
2
5
I
N
C
I
D
D
7
2
1
S
P
E
E
D
I
S
P
E
R
S
I
O
N
3
R
E
F
R
A
C
T
I
O
4
C
R
I
T
I
C
A
L
N
T
6
R
E
D
O
U
N
D
A
R
Y
8
M
E
D
I
U
M
E
B
N
1
This changes when a wave reaches a boundary.
2
This effect produces a rainbow when white light goes through a prism.
3
This happens at a boundary when the incident angle is small.
4
At this angle light travels along the boundary.
5
This is the angle between the normal line and the wave going towards a boundary.
6
The colour that is refracted the least through a prism.
7
The junction between air and plastic is an example of a ___________
8
The scientific name for the stuff a wave is travelling through.
True or false? Put T or F in the boxes.
Refraction occurs at a boundary due to the change in a wave’s frequency.
When a wave’s speed decreases it bends towards the normal.
3
[F/H]
F
T
Waves refract the most when there is a small change in speed.
F
Dispersion occurs because colours have different wave speeds.
T
Fill in the gaps using words from the list. Choose four different words from the list.
higher
lower
greater
lower
[H]
higher
Total internal reflection can only occur when a ray of light travels from a medium with
a higher refractive index into a medium with a lower one. Also the angle of incidence
must be greater than the critical angle. The higher the refractive index of a medium the
lower its critical angle.
39 of 40
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Physics
Self-assessment quiz: answers
P5h Foundation and Higher
Lenses
1
Complete the following ray diagram and mark the focal point on the diagram.
[F/H]
focal point
2
Complete the following sentences using the words given.
convex
real
converging
focal length
smaller
[F]
centre
(a) A convex lens sometimes known as a converging lens.
(b) The distance from the centre of the lens to the focal point is known as the focal
length.
(c) A thick lens will have smaller focal length than a thin lens.
(d) Cameras and projectors both use convex lenses and produce real images.
3
Complete the following ray diagram by drawing two rays from the top of the object to
the top of the image.
[H]
F = focal
point
F
4
A convex lens produces an image 8 cm high of an object that was originally 4 cm high.
Calculate the magnification.
[H]
x2
5
How would you adjust a camera lens to produce a focused image on the film?
[F/H]
By moving the lens towards or away from the film (not the object!)
40 of 40
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This document may have been altered from the original.