Physics
for the
Cambridge iGCSE Syllabus
Contents
Topic
Page Number
Topic 1
General Physics
2
Past Paper Questions
26
Topic 2
Thermal Physics
70
Past Paper Questions
83
Topic 3
Waves
108
Past Paper Questions
120
Topic 4
Electricity & Magnetism
146
Past Paper Questions
173
Topic 5
Atomic Physics
214
Past Paper Questions
221
Appendix
Topic 1:
General Physics
Length
•
Length is a distance measurement and its SI unit is the metre (m).•
Length is usually measured with a rule, a tape or a trundle wheel.•
Small lengths are measured with a micrometer or callipers where a greater precision is available.•
In certain circumstances, average lengths can be found be measuring a number of distances together then dividing by the number of objects eg a ream of paper.Time
•
Time is usually measured with a stopclock. Human timing is not precise because of reaction times.•
The SI unit for time is seconds (s).•
For repeated events, an average time can be found by measuring a number of repeats then dividing by the number of cycles eg. a pendulum.1
2
Speed
•
Speed tells us how fast something is moving.•
It is measured in m/s.•
Average speed is calculated using:Average Speed (m s) =Distance moved (m) time taken (s)
Examples
•
A sprinter runs 100m in 10s. Calculate his average speed.•
A bird flies 60m in 5s. Calculate its average speed.•
Pupils measured their times taken to travel differentdistances doing various exercises. Their results are recorded in the table. Complete the table.
Exercise Distance (m) Time (s) Speed (m/s)
Running 70 12
Walking 10 35
Hopping 50 110
Acceleration
•
Acceleration tells us how quickly something is changing its speed.•
It is measured in m/s2.•
Acceleration is calculated using:Average Acceleration (m s2
) =Change in speed ( m s ) time taken (s)
Example:
•
A motorbike goes from 10m/s to 35 m/s in 8s. Calculate his acceleration4
5
Distance/time graphs
•
A Distance/time graph is a way of representing motion.time distance
stationary Constant speed (fast)
Constant speed (slow) Acceleration
Calculations with distance/
time graphs
•
Speed is given by the gradient of the distance/time graph.Distance/time graph questions
•
Describe the motion of the following bodies:t d (a) t d (b) t d (c)
7
8
9
Distance/Time Graph
questions
•
Calculate the speeds of the car and the bike below: Car Bike 0 125 250 375 500 0 5 10 15 20 25 Distance (m) Time (s)Speed/time graphs
•
A Speed/time graph is an alternative way
of representing motion.
time speed Constant speed Rapid acceleration Gradual acceleration Non-Uniform Acceleration StationaryCalculations with speed/time
graphs
•
Acceleration is given by the gradient of the speed/ time graph.•
Distance is given by the Area under the speed/time graph.10
11
Speed/time graph questions
•
Describe the motion of the following
bodies:
t v (a) t v (b) t v (c)Speed/time calculation.
•
(a) Find the acceleration of the bike in the first 10s.•
(b) Find the distance moved by the bike in the first 20s.0 3.75 7.50 11.25 15.00 0 5 10 15 20 Motion of a bike Speed (m/s) time (s)
The Ticker-Timer
•
The ticker-timer runs at 50Hz. It puts 50 dots on the tape every second.•
If the tape moves quickly, the dots are widely spaced.•
If the tape moves slowly, the dots are closeTicker Timer
Ticker Tape
13
14
Ticker Tape
Slow moving ticker-tapeFast moving ticker-tape
Charts
•
By cutting the tape into 5 space strips and arranging them side-by-side we can get a chart representing the motion.•
Each strip will represent 0.1s of motion.Typical Shapes of Charts
16
17
Calculations
•
Since each strip represents 0.1s of motion, and we can measure the length of the strips in cm, we can use speed=distance/time to calculate the speeds.Scalars and Vectors
• A SCALAR quantity has a size (Magnitude), but no direction.• Examples of scalar Quantities are temperature, time, energy and power. • A VECTOR quantity has both a magnitude and a direction. Vectors
are often represented with an arrowed line. The direction of the arrow is the direction of the vector and the length of the line represents the size of the vector.
• Examples of vectors are force, momentum and velocity.
F Big Stone Sand Bucket Small Stone
1
Small Stone Paper Tray Sand Bucket2
Vacuum Paper Coin3
19
20
21
Gravity
•
Experiment 1•
Both Stones Land at the same time.•
Gravity makes them fall at the same rate.•
Experiment 2•
Stone landed first.•
Air Resistance slowed down the paper tray.•
Experiment 3•
Both coin & paper land at the same time.Weight and Mass
•
Weight is a force. It tells us how heavy something is. It is measured in newtons (N). It changes depending upon the size of gravity. (Trip to the moon)•
Mass tells us how much substance there is in an object. It is measured in kilograms (kg). It never changes.•
On Earth we multiply mass by 10 to get weight.Density
•
Density tells us how compact the mass is in a material.•
It is given by:or
•
Stick to one set of units.•
Water has a density of 1000 kg/m3 or 1 g/cm3.•
Materials with a smaller density than water will float, materials with a higher density than water will sink. Density ( kg m3)= mass(kg) volume(m3) Density ( g cm 3)= mass(g) volume(cm3)22
23
24
Density Calculation
Complete the following table:Object Density (kg/ m3) Mass (kg) Volume (m3) A 4000 2 B 8000 4 C 2000 1000 D 2000 4
a) Which object has the greatest mass? b) Which has the smallest volume?
c) Which objects could be made of the same substance? d) Which object would float on water?
Irregular objects
•
The volume of a liquid can be determined using a measuring cylinder.•
The volume of irregular objects has to be found by displacement.Hooke’s Law
•
Hooke’s Law states that the extension in a spring is proportional to the load applied.The constant of proportionality is called the Spring Constant. load α extension or F= kx
25
26
27
Extension/Force Graphs
•
A graph can be plotted to show how Force varies with extension for a spring.•
The graph shows proportionality up to a point called the ‘proportionality limit’.•
With increased extension, the spring will reach a point at which it will not return to its original shape. This is called the elastic limit. The spring shows ‘plastic’ behaviour beyond here.Load/Extension Graphs
•
A graph can be plotted to show how extension varies with load for a spring.•
The graph shows proportionality up to a point called the ‘proportionality limit’.•
With increased load, the spring will reach a point at which it will not return to its original shape. This is called the elastic limit. The spring shows ‘plastic’ behaviour beyond here.Extension/Force Graphs
extension Load 0 Proportionality Limit Linear Region28
29
30
Newton’s 1
st
Law
•
If the forces around an object balance (resultant 0N), then it will either:•
Remain at rest or•
Move at a constant speed in a straight line.•
(This is the same as saying constant velocity).Examples of 1
st
Law
Remains at rest
Moves at a
constant speed
in a straight
line
Normal Air Air Gravity Normal GravityOil Tube Experiment
Gravity Fluid Resistance
Falls at a
constant
speed in a
straight line.
31
32
33
Unbalanced Forces
•
If the forces around an object do not balance, then they will cause the object to accelerate (ordecelerate).
•
The rate of the acceleration depends upon the mass of the object.•
The quantities are linked by the following equation:F(N )
= m(kg) × a(m s
2)
Questions
•
1. What will be the Force needed to produce an acceleration of 2m/s2 on a mass of 4kg?•
2. What will be the Force needed to produce an acceleration of 5m/s2 on a mass of 42kg?•
3. What will be the acceleration produced when a Force of 50N acts upon a mass of 10kg?Newton’s Laws Calculation
A front wheel drive car is travelling at constant velocity. Q is the force of the air on the moving car. P is the total upward force on both front wheels.
(a) Explain why P= 4 000N, Q= 400N (b) Calculate the mass of the car.
(c) The 400 N driving force to the left is suddenly doubled. (i) Calculate the resultant forward driving force. (ii) Calculate the acceleration of the car.
(iii) Sketch a graph showing how the velocity of the car changes with time (start the graph just before the driving force is doubled.)
400 N P 6000 N Q 10 000 N
34
35
36
Circular Motion
• When an object is moving in a circle, it must be experiencing a force TOWARDS THE CENTRE of the circle.
• We call this the CENTRIPETAL Force.
• This should not be confused with CENTRIFUGAL Force. • The centripetal force is directed at right angles to the object’s
velocity.
object’s path
direction of force
Questions
•
For each of the following examples, draw a sketch to show the situation, name the force providing the circular motion, and indicate its direction:•
A) The Earth orbiting the Sun.•
B) A car rounding a bend.•
C) A hammer-thrower winding into his throw.Moments
•
A moment is a turning force.•
It is given by:Moment(Nm)
= Force(N) × distance(m)
37
38
Example
•
Calculate the moment produced:0.1m
100N
The Principle of Moments
•
If a lever is balanced (in equilibrium) then the total clockwise moments equal the total anti-clockwise moments. It will not move.•
Because of Newton’s 1st Law, the forces must also balance. Anti-clockwise moments Clockwise momentsResults
Left-Hand Side Right-Hand Side Weight Distance W x d Weight Distance W x d
2
8
4
?
3
4
?
6
5
2
2
?
6
3
?
2
40
41
42
Moments Questions
•
1. Explain why a mechanic would choose a long-arm spanner to undo a tight nut.•
2. In the following diagram, what is the weight of X ?X 4N 20 cm 25 cm
Uses of Levers
•
Spanner•
Nutcracker•
ScissorsCentre of Mass
•
Centre of mass is the point on an object that is the ‘average’ position of the mass of the object.•
The centre of gravity is a point on all objects through which forces appear to act.•
The two points are the same.•
The centres of mass of regular objects are obvious. They always lie on a line of symmetry.•
They are the point under which we place a pivot to balance the object.43
44
Regular Objects
Stability
•
Stability tells us how secure something is on the ground.•
If something is stable, then it will not topple easily.•
There are two factors to consider when changing the stability of an object:•
The area of the object’s base.•
The position of the centre of mass of the object.•
A stable object will have a BIG base, and a LOW centre of gravity.Simple Addition
•
If two vectors are parallel, then they can be simply added or subtracted to give a resultant.3N 5N 2N RESULTANT
46
47
48
2D-Addition
•
If the vectors are not parallel we have to draw a scale diagram and add the vectors to give a resultant.3m/s 2m/s
RESULTANT
3m/s
2m/s
Examples
•
1. A plane flies North at 40m/s. The wind blows to the East at 15 m/s. Calculate the overall velocity.•
2i). A falling ball has a weight of 10N and and air resistance of 2N. What the effective downward force on it?•
ii) A wind blows to the left with a force of 2N. Using a vector diagram, calculate the resultant force on the ball.Energy
Forms
Elastic
Potential
Energy
Heat
Kinetic
Electricity
Sound
Gravitational
Potential
Energy
Chemical
Potential
Energy
Light
49
50
51
Energy Transfers
•
When any physical process takes place, there is a transfer of energy from one form to another.•
This can be shown in an energy flow diagram:T.V Electricity
Light Sound
Heat
Examples of Energy Transfers
•
A burning match•
A lightbulb•
A petrol lawnmower•
A car•
Headphones•
A microphone•
A waterfallKinetic Energy
•
All objects that are moving have kinetic energy.•
It depends on the mass of the object and its speed.•
It is measured in joules.KE
=
1
2
mv
252
53
54
Gravitational Energy
•
Gravitational energy is stored in objects that are at a height.•
It depends upon the mass of the object, and how high the object is.•
It measured in joules.GPE
= mgh
The Principle of the
Conservation of Energy
•
Energy cannot be created or destroyed, it simply moves from one form to another.•
When energy moves from one form to another, the total AMOUNT of energy remains the same.•
A certain amount of heat energy is always lost to the surroundings in any process.Efficiency
• Efficiency tells us how effective a process or energy transfer is.
• The more useful energy that is produced, for the least input energy, the more efficient the process is.
• Efficiency has no unit, and can be expressed as a decimal or percentage. • It can be the ratio of power output to input, or energy output to input
for a process Efficiency= output input (×100)
55
56
57
Work Done
•
Work is a type of energy change and is measured in Joules.•
For work to be done, a force must be acting upon an object as it moves through a distance.•
The Work Done is given by:Work Done (J )=Force(N )
× Distance(m)
Power
•
Power is the rate at which energy is transferred.•
It is also the rate at which Work is done.•
The unit for Power is Watts (W).•
Power is calculated from either:or
Power(W )=Energy Change(J ) Time Taken(s)
Power(W )=Work Done(J ) Time Taken(s)
Calculating Personal Power
• Measure your weight in newtons. • Measure the height of the steps in metres.
• Measure the time taken to climb the steps in seconds. • Calculate the Work Done in joules.
• Calculate the Power of your legs in Watts.
height time
weight
58
59
Pressure
•
Pressure tells us how concentrated a force is.•
It is calculated from:or
Stick to one set of units Pressure( N m2 )=Force(N ) Area(m2 ) Pressure( N cm 2)= Force(N ) Area(cm2)
Examples
1. Calculate the Volume of the block. 2. Calculate the block’s density. 3. Calculate the block’s weight.
4. Calculate the area in contact with the ground.
1cm
1cm 2cm
20g
Examples
•
Why do camels have large flat feet?•
Why is it easier to walk in snow shoes in the snow?61
62
Pressure in Liquids
Pressure in a liquid is due to the weight of the liquid above a point.
Pressure increases with depth.
Pressure will also increase with density of liquid (more weight).
We can calculate pressure from:
P
=
ρgd
Direction
•
The pressure in a liquid acts in ALL directions equally at a point.•
This is why bubbles are spherical.Questions
•
1a). Draw a diagram of the cross section of a dam.•
b) Explain why it has this shape.•
2. Calculate the pressure on a scuba diver at a depth of 20m. (The density of water is 1000kg/m3)•
3. Describe a demonstration to show that Pressureincreases with depth in a liquid.
64
65
Non-Renewable Energy
Resources
•
Non-Renewable resources are resources that are used up and cannot be easily replaced. Examples are fossil fuels and Nuclear fuels.Renewable Energy Resources
•
Renewable Energy Resources are energy resources that keep running and do not run-out easily.The Energy Crisis • Transport • Electricity • Fossil Fuels • Pollution • Depletion Energy usage • Energy Density • Pollution • Safety Nuclear Fission Renewable Alternatives • Advantages • Unreliable • Not Controllable • Energy Density Nuclear Fusion • Safety • Pollution • Problems
67
68
69
General Physics
Quantity and
symbol
Definition/Word equation
Symbol
equation
Units
Scalar Quantities Scalar quantities only have a magnitude.
Vector Quantities
Vector quantities have a magnitude, a direction
and a point of application.
Average Speed, s
Speed is the rate of change of distance. It is a
scalar quantity.
Speed = Total distance
Total time
For constant acceleration situations, the
average speed is also equal to the average of
the initial and final speeds.
s = initial speed + final speed
2
s = d
t
s = u + v
2
m/s
cm/s
km/h
Velocity
Velocity is the rate of change of displacement.
It is speed in a given direction. A vector
quantity.
m/s
cm/s
km/h
Acceleration, a
Acceleration is the rate of change of velocity.
Acceleration = Final velocity – initial velocity
Time
a = v – u
t
m/s
2Mass, m
Mass is a property of a body that resists change
in motion.
Weight, W, F
Weight is the force on a mass due to the
gravitational field of the Planet. It changes
from planet to planet. Weights can be
compared using a balance.
Weight = mass x acceleration due to gravity
Weight = mass x gravitational field strength
W = m x g
Newtons,
N
Density, ρ
Density is the mass per unit volume.
Density = mass
volume
ρ = m
V
Kg/m
3g/cm
3Force, F
A force is a push or a pull; it can change the
shape, direction, and/or speed of an object.
Force = mass x acceleration
F = m a
Newtons,
N
Load, (Hookes
law)
Load = spring constant x extension
Load α extension
F = k l
F α l
Newtons,
N
Moment
A moment is the turning affect of a force.
Moment = force x perpendicular distance from
the pivot
Moment = F d
Nm
Equilibrium
When there is no resultant force AND no
resulting turning affect, a system is in
equilibrium.
Work done, W, E
Work done = Force x distance in the direction
of the force = change in energy
W = F d = ΔE
Joules, J
Kinetic energy,
KE
Kinetic energy is the energy of a body due to
its motion.
Kinetic energy = ½ x mass x velocity
2KE = ½ m v
Gravitational
energy, GPE
Gravitational potential energy is the energy of
a body due to its position in the gravitational
field.
Gravitational energy =mass x acceleration due
to gravity x height gained/lost
GPE = m g h
Joules, J
Efficiency
Efficiency = useful output x 100%
total input
%
Power, P
Power is the rate at which energy is converted.
Power = work done
time taken
Power = energy change
time taken
P = E
t
Watts, W
Pressure, p, P
Pressure = force
area
A
P = F
N/m
2Pascals,
Pa
millibar
Fluid Pressure, p,
P
Pressure = density of fluid x acceleration due
to gravity x height of fluid above
P = ρ g h
N/m
2Pascals,
Pa
Millibar
iGCSE Physics
Past Paper Questions
Paper 1 Compilation
General Physics
2
0625/1/M/J/02
1 The diagram shows the level of liquid in a measuring cylinder.
What is the volume of the liquid?
A 24 cm3 B 28 cm3 C 29 cm3 D 32 cm3
2 A cylindrical can is rolled along the ruler shown in the diagram.
The can rolls over twice.
What is the circumference (distance all round) of the can?
A 13 cm B 14 cm C 26 cm D 28 cm
0 cm 5 10 15 20 25 30 cm
mark on can
can rolled
starting position final position
30 20 cm3 liquid
1.
2.
3
0625/1/M/J/02 [Turn over
3 The graph shows how the speed of a car changes with time.
Which of the following gives the distance travelled in time interval OR?
A the area OPQR
B the length PQ
C the length (QR – PO)
D the ratio QR/PO
4 A snail crosses a garden path 30 cm wide at a speed of 0.2 cm/s.
How long does the snail take?
A 0.0067 s B 6.0 s C 15 s D 150 s
5 What are correct units used for mass and for weight?
30 cm movement of snail snail speed P Q R O time mass weight A kg kg B kg N C N kg D N N
3.
4.
5.
4
0625/1/M/J/02
6 Two objects X and Y are placed on a beam as shown. The beam balances on a pivot at its centre.
What does this show about X and Y?
A They have the same mass and the same density.
B They have the same mass and the same weight.
C They have the same volume and the same density.
D They have the same volume and the same weight.
7 A shop-keeper places two identical blocks of cheese on a set of scales and notices that their combined mass is 240 g. Each block measures 2.0 cm x 5.0 cm x 10.0 cm.
What is the density of the cheese?
A 0.42 g / cm3 B 0.83 g / cm3 C 1.2 g / cm3 D 2.4 g / cm3
8 The table shows the length of a wire as the load on it is increased.
Which subtraction should be made to find the extension caused by the 20 N load?
A 54.1 cm – 0 cm B 54.1 cm – 50.0 cm C 54.1 cm – 52.1 cm D 56.3 cm – 54.1 cm g X Y pivot load / N 0 10 20 30 length / cm 50.0 52.1 54.1 56.3
6.
7.
8.
5
0625/1/M/J/02 [Turn over
9 A child tries to push over a large empty oil drum.
Where should the drum be pushed to topple it over with least force?
10 Which device is designed to convert chemical energy into kinetic energy (energy of motion)? A an a.c. generator
B a battery-powered torch
C a car engine
D a wind-up mechanical clock
11 A ball is released from rest and rolls down a track from the position shown.
What is the furthest position the ball could reach?
ball starts here A B C D A B C D
9.
10.
11.
6
0625/1/M/J/02
12 Two sharp nails and two blunt nails are held on a piece of wood. Each nail is hit with the same
hammer with the same amount of force.
When it is hit, which nail causes the greatest pressure on the wood?
13 The diagram shows a manometer connected to a container of carbon dioxide.
Which statement correctly describes the pressure exerted by the carbon dioxide?
A It is equal to the atmospheric pressure.
B It is equal to 5 cm of mercury.
C It is equal to 5 cm of mercury above atmospheric pressure.
D It is equal to 5 cm of mercury below atmospheric pressure. carbon dioxide container mercury manometer 5 cm A B hammer sharp nails C D hammer blunt nails
12.
13.
2
0625/01/M/J/03
1 A glass tank contains some water.
The length QR and the width RS of the tank are known.
What other distance needs to be measured in order to be able to calculate the volume of the water?
A ST B SV C TU D TV
2 A stopwatch is used to time a race. The diagrams show the watch at the start and at the end of the race.
How long did the race take?
A 45.7 s B 46.0 s C 46.5 s D 47.0 s 45 30 15 seconds start 50 55 60 5 10 20 25 35 40 45 30 15 seconds end 50 55 60 5 10 20 25 35 40 water Q R S T V U
14.
15.
3
0625/01/M/J/03 [Turn over
3 The diagram shows a speed-time graph for a body moving with constant acceleration.
What is represented by the shaded area under the graph?
A acceleration
B distance
C speed
D time
4 A tunnel has a length of 50 km. A car takes 20 min to travel between the two ends of the tunnel. What is the average speed of the car?
A 2.5 km / h
B 16.6 km / h
C 150 km / h
D 1000 km / h
5 Which statement is correct?
A Mass is a force, measured in kilograms.
B Mass is a force, measured in newtons.
C Weight is a force, measured in kilograms.
D Weight is a force, measured in newtons. speed time 0 0
16.
17.
18.
4
0625/01/M/J/03
6 Three children, X, Y and Z, are using a see-saw to compare their weights.
Which line in the table shows the correct order of the children’s weights?
7 What apparatus is needed to determine the density of a regularly-shaped block?
A a balance and a ruler
B a balance and a forcemeter (spring balance)
C a measuring cylinder and a ruler
D a measuring cylinder and a beaker
8 A spring is suspended from a stand. Loads are added and the extensions are measured.
Which graph shows the result of plotting extension against load?
0 0 extension load A 0 0 extension load B 0 0 extension load C 0 0 extension load D spring stand loads rule X Y Y Z X Z heaviest
←→
lightest A X Y Z B X Z Y C Y X Z D Y Z X19.
20.
21.
5
0625/01/M/J/03 [Turn over
9 A student uses a stand and clamp to hold a flask of liquid. Which diagram shows the most stable arrangement?
10 What is the source of the energy converted by a hydro-electric power station? A hot rocks
B falling water
C oil
D waves
11 A labourer on a building site lifts heavy concrete blocks onto a lorry. Lighter blocks are now lifted
the same distance in the same time.
What happens to the work done in lifting each block and the power exerted by the labourer?
A B C D
work done in power exerted by lifting each block labourer
A decreases decreases
B decreases remains the same
C increases increases
D remains the same increases
22.
23.
6
0625/01/M/J/03
12 The diagram shows an instrument used to measure gas pressure.
What is the instrument called?
A ammeter
B barometer
C manometer
D thermometer
13 The diagrams show two divers swimming in the sea and two divers swimming in fresh water. Sea
water is more dense than fresh water.
On which diver is there the greatest pressure?
14 When water evaporates, some molecules escape.
Which molecules escape?
A the molecules at the bottom of the liquid with less energy than others
B the molecules at the bottom of the liquid with more energy than others
C the molecules at the surface with less energy than others
D the molecules at the surface with more energy than others
fresh water C D 2 m 0 m 4 m 6 m sea water A B 2 m 0 m 4 m 6 m liquid
25.
26.
27.
2
U CLE S 2004 0625/01/M/J/04
1 The diagram shows a measuring cylinder.
10 20 30 40 50 60 70 80 90 100
Which unit would be most suitable for its scale?
A mm2 B mm3 C cm2 D cm3
2 A piece of cotton is measured between two points on a ruler.
1
cm 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
cotton
When the length of cotton is wound closely around a pen, it goes round six times.
pen six turns of cotton
What is the distance once round the pen?
A 2.2 cm B 2.6 cm C 13.2 cm D 15.6 cm
28.
3
UCLES 2004 0625/01/M/J/04 [Turn over
3 The diagram shows the speed-time graph for an object moving at constant speed.
2 0 0 3 4 time / s speed m / s 1 1 2
What is the distance travelled by the object in the first 3 s?
A 1.5 m B 2.0 m C 3.0 m D 6.0 m
4 A small steel ball is dropped from a low balcony.
Ignoring air resistance, which statement describes its motion?
A It falls with constant acceleration.
B It falls with constant speed.
C It falls with decreasing acceleration.
D It falls with decreasing speed.
5 Which statement about the mass of a falling object is correct?
A It decreases as the object falls.
B It is equal to the weight of the object.
C It is measured in newtons.
D It stays the same as the object falls.
30.
31.
4
UCLES 2004 0625/01/M/J/04
6 The weights of four objects, 1 to 4, are compared using a balance.
1
2
3
2 4
2
Which object is the lightest?
A object 1 B object 2 C object 3 D object 4 7 Which of the following is a unit of density?
A cm3/ g B g / cm2 C g / cm
3
D kg / m2
8 A piece of card has its centre of mass at M.
Which diagram shows how it hangs when suspended by a thread?
A B C D
M M
M
M
9 An experiment is carried out to measure the extension of a rubber band for different loads. The results are shown below.
load / N 0 1 2 3
length / cm 15.2 16.2 18.6
extension / cm 0 1.0 2.1 3.4
Which figure is missing from the table?
A 16.5 B 17.3 C 17.4 D 18.3
33.
34.
35.
5
UCLES 2004 0625/01/M/J/04 [Turn over
10 The diagram shows a man diving into water.
Which form of energy is increasing as he falls? A chemical
B gravitational C kinetic D strain
11 A boy and a girl run up a hill in the same time.
boy weighs 600 N girl weighs 500 N
The boy weighs more than the girl.
Which statement is true about the power produced? A The boy produces more power.
B The girl produces more power. C They both produce the same power.
D It is impossible to tell who produces more power.
36.
37.
6
U CLE S 2004 0625/01/M/J/04
12 The diagram shows a simple mercury barometer. The barometer reading is h cm of mercury.
mercury S
h
What is the pressure at S? A approximately zero B atmospheric pressure
C atmospheric pressure + h cm of mercury D h cm of mercury
13 Two boys X and Y each have the same total weight and are standing on soft ground.
X Y
Which boy is more likely to sink into the soft ground and why? boy more likely to sink pressure on soft ground A X larger than Y B X smaller than Y C Y larger than X D Y smaller than X
39.
40.
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© UCLES 2005 0625/01/M/J/05
1 A decorator wishes to calculate the area of a bathroom tile so that he can estimate the amount of adhesive that he needs to buy.
What must he use?
A a measuring cylinder only
B a ruler only
C a measuring cylinder and a clock only
D a measuring cylinder and a ruler only
2 The three balls shown are dropped from a bench.
aluminium lead wood
Which balls have the same acceleration?
A aluminium and lead only
B aluminium and wood only
C lead and wood only
D aluminium, lead and wood
3 A car accelerates from traffic lights. The graph shows how the car’s speed changes with time.
time/s 20 10 0 0 speed m/s
How far does the car travel before it reaches a steady speed?
A 10m B 20m C 100m D 200m
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43.
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© UCLES 2005 0625/01/M/J/05 [Turn over
4 Which statement is correct?
A The mass of a bottle of water at the North Pole is different from its mass at the Equator.
B The mass of a bottle of water is measured in newtons.
C The weight of a bottle of water and its mass are the same thing.
D The weight of a bottle of water is one of the forces acting on it.
5 Two blocks X and Y are placed on a beam as shown. The beam balances on a pivot at its centre.
X
Y
pivot
What does this show about X and Y?
A They have the same mass and the same density.
B They have the same mass and the same weight.
C They have the same volume and the same density.
D They have the same volume and the same weight.
6 The masses of a measuring cylinder before and after pouring some liquid into it are shown in the diagram. 200 100 cm3 mass = 80 g 200 100 cm3 mass = 180 g liquid
What is the density of the liquid?
A 120 100 g/cm3 B 140 100 g/cm3 C 120 180 g/cm3 D 140 180 g/cm3
45.
46.
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© UCLES 2005 0625/01/M/J/05
7 A girl and a boy are pulling in opposite directions on a rope. The forces acting on the rope are shown in the diagram.
200N
rope
150N
girl boy
Which single force has the same effect as the two forces shown?
A 50N acting towards the girl
B 350N acting towards the girl
C 50N acting towards the boy
D 350N acting towards the boy
8 Objects with different masses are hung on a 10cm spring. The diagram shows how much the spring stretches. 100g M 10cm 20cm 30cm
The extension of the spring is directly proportional to the mass hung on it.
What is the mass of object M?
A 110g B 150g C 200g D 300g
48.
49.
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© UCLES 2005 0625/01/M/J/05 [Turn over
9 What is designed to change electrical energy into kinetic energy?
A capacitor
B generator
C motor
D transformer
10 A power station uses nuclear fission to obtain energy.
In this process, nuclear energy is first changed into
A chemical energy.
B electrical energy.
C gravitational energy.
D internal energy.
11 A ball is released from rest and rolls down a track from the position shown.
What is the furthest position the ball could reach?
A B C D ball starts here
51.
52.
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© U CLE S 2005 0625/01/M/J/05
12 A water manometer is used to measure the pressure of a gas supply to a house. It gives a reading of h cm of water.
gas supply
hcm
Why is it better to use water rather than mercury in this manometer? A h would be too large if mercury were used.
B h would be too small if mercury were used.
C The tube would need to be narrower if mercury were used. D The tube would need to be wider if mercury were used.
13 A farmer has two carts. The carts have the same weight, but one has four narrow wheels and the other has four wide wheels.
narrow wheel wide wheel
In rainy weather, which cart sinks less into soft ground, and why?
cart wheels why
A narrow greater pressure on the ground B narrow less pressure on the ground C wide greater pressure on the ground
D wide less pressure on the ground
54.
55.
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© UCLES 2006 0625/01/M/J/06
1 A measuring cylinder contains some water. When a stone is put in the water, the level rises.
150 100 50 cm3 150 100 50 cm3 200 200 stone
What is the volume of the stone?
A 50cm3 B 70cm3 C 75cm3 D 125cm3
2 The graph represents the movement of a body accelerating from rest.
1 2 3 4 5 10 8 6 4 2 0 time/s speed m/s
After 5 seconds how far has the body moved?
A 2m B 10m C 25m D 50m
3 A child is standing on the platform of a station, watching the trains.
A train travelling at 30m/s takes 3s to pass the child.
What is the length of the train?
A 10m B 30m C 90m D 135m
57.
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© UCLES 2006 0625/01/M/J/06 [Turn over
4 Below are four statements about the effects of forces on objects.
Three of the statements are correct.
Which statement is incorrect?
A A force can change the length of an object.
B A force can change the mass of an object.
C A force can change the shape of an object.
D A force can change the speed of an object.
5 A simple balance has two pans suspended from the ends of arms of equal length. When it is balanced, the pointer is at 0.
0
pointer
pan X pan Y
arm pivot
Four masses (in total) are placed on the pans, with one or more on pan X and the rest on pan Y.
Which combination of masses can be used to balance the pans?
A 1g, 1g, 5g, 10g
B 1g, 2g, 2g, 5g
C 2g, 5g, 5g, 10g
D 2g, 5g, 10g, 10g
6 A person measures the length, width, height and mass of a rectangular metal block.
Which of these measurements are needed in order to calculate the density of the metal?
A mass only
B height and mass only
C length, width and height only
D length, width, height and mass
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© UCLES 2006 0625/01/M/J/06
7 Two forces act on an object.
In which situation is it impossible for the object to be in equilibrium?
A The two forces act in the same direction.
B The two forces act through the same point.
C The two forces are of the same type.
D The two forces are the same size.
8 The diagram shows four models of buses placed on different ramps.
centre
of mass of masscentre of masscentre of masscentre
How many of these models will fall over?
A 1 B 2 C 3 D 4
9 Which form of energy do we receive directly from the Sun?
A chemical
B light
C nuclear
D sound
10 A labourer on a building site lifts a heavy concrete block onto a lorry. He then lifts a light block the same distance in the same time.
Which of the following is true?
work done in lifting the blocks
power exerted by labourer
A less for the light block less for the light block
B less for the light block the same for both blocks
C more for the light block more for the light block
D the same for both blocks more for the light block
63.
64.
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© U CLE S 2006 0625/01/M/J/06 [Turn over
11 The diagram shows a thick sheet of glass.
Which edge must it stand on to cause the greatest pressure?
A
D
C
B
12 A manometer is being used to measure the pressure of the gas inside a tank. A, B, C and D show the manometer at different times.
At which time is the gas pressure inside the tank greatest?
gas
A B C D
13 Brownian motion is seen by looking at smoke particles through a microscope. How do the smoke particles move in Brownian motion?
A all in the same direction B at random
C in circles
D vibrating about fixed points
67.
iGCSE Physics
Past Paper Questions
Paper 3 Compilation
General Physics
2
0625/3/M/J/02
1 A group of students attempts to find out how much power each student can generate. The students work in pairs in order to find the time taken for each student to run up a flight of stairs.
The stairs used are shown in Fig. 1.1.
Fig. 1.1
(a) Make a list of all the readings that would be needed. Where possible, indicate how the
accuracy of the readings could be improved.
... ... ... ... ... ... [4]
(b) Using words, not symbols, write down all equations that would be needed to work out
the power of a student.
... ... ... [2]
(c) (i) When the student has reached the finishing point and is standing at the top of the
stairs, what form of energy has increased to its maximum?
...
(ii) Suggest why the total power of the student is greater than the power calculated by
this method. ... ... [3] starting point finishing point For Examiner’s Use
1.
3
0625/3/M/J/02 [Turn over
2 A small rubber ball falls vertically, hits the ground and rebounds vertically upwards. Fig. 2.1 is the speed-time graph for the ball.
Fig. 2.1
(a) Using information from the graph, describe the following parts of the motion of the ball. (i) part AB ... ... ... (ii) part DE ... ... ... [3]
(b) Explain what is happening to the ball along the part of the graph from B through C to D.
... ... ... [2]
(c) Whilst the ball is in contact with the ground, what is the (i) overall change in speed,
change in speed = ...
(ii) overall change in velocity?
change in velocity = ... [2] 10 8 6 4 2 0 0 0.5 1.0 1.5 2.0 time / s speed m / s B D C E A For Examiner’s Use
2.
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0625/3/M/J/02
(d) Use your answer to (c) to explain the difference between speed and velocity.
... ... ... [2]
(e) Use the graph to calculate the distance travelled by the ball between D and E.
distance travelled = ...[2]
(f) Use the graph to calculate the deceleration of the ball between D and E.
deceleration = ...[2]
For Examiner’s
2
0625/3/M/J/03
1 Fig. 1.1 shows apparatus that may be used to compare the strengths of two springs of the same size, but made from different materials.
Fig. 1.1
(a) (i) Explain how the masses produce a force to stretch the spring.
...
(ii) Explain why this force, like all forces, is a vector quantity.
... ... [2]
(b) Fig. 1.2 shows the graphs obtained when the two springs are stretched.
Fig. 1.2 0 0 5 10 15 20 force/N 10 20 30 40 extension/mm spring 1 spring 1 spring 2 spring 2 spring 1 spring 2 spring masses scale For Examiner’s Use
3.
3
0625/3/M/J/03 [Turn over
(i) State which spring is more difficult to extend. Quote values from the graphs to support your answer.
... ... ... ...
(ii) On the graph of spring 2, mark a point P at the limit of proportionality. Explain your choice of point P.
... ... ...
(iii) Use the graphs to find the difference in the extensions of the two springs when a force of 15 N is applied to each one.
difference in extensions = ... [6]
2 The speed of a cyclist reduces uniformly from 2.5 m/s to 1.0 m/s in 12 s.
(a) Calculate the deceleration of the cyclist.
deceleration = ...[3]
(b) Calculate the distance travelled by the cyclist in this time.
distance = ...[2]
For Examiner’s
Use
4
0625/3/M/J/03
3 Fig. 3.1 shows the arm of a crane when it is lifting a heavy box.
Fig. 3.1
(a) By the use of a scale diagram (not calculation) of the forces acting at P, find the weight
of the box. [5] 40° 30° 950 N 1220 N P box For Examiner’s Use
5.
5
0625/3/M/J/03 [Turn over
(b) Another box of weight 1500 N is raised vertically by 3.0 m. (i) Calculate the work done on the box.
work done = ...
(ii) The crane takes 2.5 s to raise this box 3.0 m. Calculate the power output of the crane.
power = ... [4]
4 Fig. 4.1 shows a sealed glass syringe that contains air and many very tiny suspended dust particles.
Fig. 4.1
(a) Explain why the dust particles are suspended in the air and do not settle to the bottom.
... ... ... ...[3]
(b) The air in the syringe is at a pressure of 2.0× 105Pa. The piston is slowly moved into the syringe, keeping the temperature constant, until the volume of the air is reduced from 80 cm3to 25 cm3. Calculate the final pressure of the air.
pressure = ...[3] syringe seal dust particles piston For Examiner’s Use
2
0625/03 M/J/04
1 Fig. 1.1 shows a cycle track.
Fig. 1.1
A cyclist starts at A and follows the path ABCDEB. The speed-time graph is shown in Fig. 1.2.
Fig. 1.2
(a) Use information from Fig. 1.1 and Fig. 1.2 to describe the motion of the cyclist (i) along AB,
...
(ii) along BCDEB.
... ... [4] 0 1 0 2 3 4 5 6 30 40 50 10 20 60 70 80 90 100 time / s speed m / s A B C D E B A B E C D v = 6 m/s For Examiner’s Use © UCLES 2004
6.
3
0625/03 M/J/04 [Turn over
(b) The velocity v of the cyclist at C is shown in Fig. 1.1.
State one similarity and one difference between the velocity at C and the velocity at E. similarity ... difference ...[2]
(c) Calculate
(i) the distance along the cycle track from A to B,
distance = ………
(ii) the circumference of the circular part of the track.
circumference = ……… [4] For Examiner’s Use © UCLES 2004
4
0625/03 M/J/04
2 Fig. 2.1 shows a rock that is falling from the top of a cliff into the river below.
Fig. 2.1
(a) The mass of the rock is 75 kg. The acceleration of free fall is 10 m/s2.
Calculate the weight of the rock.
weight = ………[1]
(b) The rock falls from rest through a distance of 15 m before it hits the water.
Calculate its kinetic energy just before hitting the water. Show your working.
kinetic energy = ………[3]
(c) The rock hits the water. Suggest what happens to the kinetic energy of the rock during
the impact. ... ... ...[3] cliff falling rock river For Examiner’s Use © UCLES 2004
7.
5
0625/03 M/J/04 [Turn over
3 A large spring is repeatedly stretched by an athlete to increase the strength of his arms. Fig. 3.1 is a table showing the force required to stretch the spring.
Fig. 3.1 (a) (i) State Hooke’s law.
... ...[1]
(ii) Use the results in Fig. 3.1 to show that the spring obeys Hooke’s law.
[1]
(b) Another athlete using a different spring exerts an average force of 400 N to enable her
to extend the spring by 0.210 m.
(i) Calculate the work done by this athlete in extending the spring once.
work done = ………
(ii) She is able to extend the spring by this amount and to release it 24 times in 60 s.
Calculate the power used by this athlete while doing this exercise.
power = ……… [4] For Examiner’s Use © UCLES 2004 extension of spring/m 0.096 0.192 0.288 0.384
force exerted to produce extension/N 250 500 750 1000
2
0625/03/M/J/05
1 A solid plastic sphere falls towards the Earth.
Fig. 1.1 is the speed-time graph of the fall up to the point where the sphere hits the Earth’s surface.
Fig. 1.1
(a) Describe in detail the motion of the sphere shown by the graph.
... ... ... ... ... [3] 0 20 P Q R S T 40 60 80 100 120 140 speed m / s 10 0 20 30 40 50 60 70 80 90 100 110 time / s For Examiner’s Use © UCLES 2005
9.
3
0625/03/M/J/05 [Turn over
(b) On Fig. 1.2, draw arrows to show the directions of the forces acting on the sphere when
it is at the position shown by point S on the graph. Label your arrows with the names of
the forces. [2]
Fig. 1.2
(c) Explain why the sphere is moving with constant speed at S.
... ... ... [2]
(d) Use the graph to calculate the approximate distance that the sphere falls (i) between R and T,
distance = ………. [2]
(ii) between P and Q.
distance = ………. [2]
For Examiner’s
Use
4
0625/03/M/J/05
2 Fig. 2.1 shows a simple pendulum that swings backwards and forwards between P and Q.
Fig. 2.1
(a) The time taken for the pendulum to swing from P to Q is approximately 0.5 s.
Describe how you would determine this time as accurately as possible.
... ... ... [2]
(b) (i) State the two vertical forces acting on the pendulum bob when it is at position R.
1. ... 2. ... [1]
(ii) The pendulum bob moves along the arc of a circle. State the direction of the
resultant of the two forces in (i).
... [1]
(c) The mass of the bob is 0.2 kg. During the swing it moves so that P is 0.05 m higher
than R.
Calculate the increase in potential energy of the pendulum bob between R and P.
potential energy = ………. [2] support string pendulum bob P R Q For Examiner’s Use © UCLES 2005
10.
5
0625/03/M/J/05 [Turn over
3 A mass of 3.0 kg accelerates at 2.0 m/s2in a straight line.
(a) State why the velocity and the acceleration are both described as vector quantities.
... ... [1]
(b) Calculate the force required to accelerate the mass.
force = ………. [2]
(c) The mass hits a wall.
The average force exerted on the wall during the impact is 120 N. The area of the mass in contact with the wall at impact is 0.050 m2.
Calculate the average pressure that the mass exerts on the wall during the impact.
pressure = ………. [2] For Examiner’s Use © UCLES 2005
11.
2 0625/03/M/J/06 For Examiner’s Use © UCLES 2006
1 A bus travels from one bus stop to the next. The journey has three distinct parts. Stated in order they are
uniform acceleration from rest for 8.0 s, uniform speed for 12 s,
non-uniform deceleration for 5.0 s.
Fig. 1.1 shows only the deceleration of the bus.
5 0 10 15 5 0 10 15 20 25 speed m/s time/s Fig. 1.1
(a) On Fig. 1.1, complete the graph to show the first two parts of the journey. [3]
(b) Calculate the acceleration of the bus 4.0 s after leaving the first bus stop.
acceleration = ...[2]
(c) Use the graph to estimate the distance the bus travels between 20 s and 25 s.
estimated distance = ...[2]
(d) On leaving the second bus stop, the uniform acceleration of the bus is 1.2 m / s2. The
mass of the bus and passengers is 4000 kg.
Calculate the accelerating force that acts on the bus.
force = ...[2]
(e) The acceleration of the bus from the second bus stop is less than that from the first bus
stop.
Suggest two reasons for this.
1. ... ... 2. ... ...[2]
12.
3 0625/03/M/J/06 [Turn over For Examiner’s Use © UCLES 2006
2 A student sets up the apparatus shown in Fig. 2.1 in order to find the resultant of the two tensions T1 and T2 acting at P. When the tensions T1, T2 and T3 are balanced, the angles between T1 and the vertical and T2 and the vertical are as marked on Fig. 2.1.
vertical board pulley pulley 69° 44° P T1 = 6.0N T2 = 8.0N T3 Fig. 2.1
In the space below, draw a scale diagram of the forces T1 and T2. Use the diagram to find the resultant of the two forces.
State
(a) the scale used, scale = ...
(b) the value of the resultant, value = ...
(c) the direction of the resultant. direction = ...
[6]
13.
4 0625/03/M/J/06 For Examiner’s Use © UCLES 2006
3 An electric pump is used to raise water from a well, as shown in Fig. 3.1. pump
ground
well
Fig. 3.1
(a) The pump does work in raising the water. State an equation that could be used to
calculate the work done in raising the water.
...[2]
(b) The water is raised through a vertical distance of 8.0 m. The weight of water raised in
5.0 s is 100 N.
(i) Calculate the work done in raising the water in this time.
work done = ...[1]
(ii) Calculate the power the pump uses to raise the water.
power = ...[1]
(iii) The energy transferred by the pump to the water is greater than your answer to (i).
Suggest what the additional energy is used for.
...[1]
14.
Topic 2:
Thermal Physics
Solids
• The particles in solids are tightly held together by strong forces.
• They vibrate around mean positions.
• The higher the temperature, the more vibrational kinetic energy the particles have.
• Solids have a rigid shape.
Liquids
• In liquids the forces are strong, but the vibrating particles are not fixed in position.
• The particles can move but they are held close to their neighbours.
• Liquids do not keep their shape.
1
2
Gases
• In gases the forces are very weak and they are virtually free to move around their container.
• The particles occasionally collide. • Gases expand to fill their container.
• The collisions between the particles and the container walls provides pressure.
Changing State
• When a material changes from one state to another, bonds are either broken or created.
• When bonds are broken, heat must be supplied. When bonds are created, heat is released.
• When materials change state there is no change in the temperature.
Phase Changes
• The phase change from solid to liquid is called ‘fusion’. • The phase change from liquid to gas is called
‘vaporisation’.
• The energy required to effect the phase change is called the ‘Latent Heat’.
• The Latent Heat required per kg is called the ‘Specific Latent Heat’.
4
5
Phases Changes (Graphical)
Temperature Time fusion vaporisation liquid waterLatent Heat Calculations
• The Specific Latent Heat of a material is given the symbol l. • From the definition, we have the following relationship:H - J m - kg l - J/kg
H
= ml
Heat Capacity
• Whilst a material is being heated within a certain state of matter, its temperature will rise.
• The temperature rise depends upon the mass of the material, the type of material and the amount of heat supplied.
• The property of a material that represents how much heat is needed to raise its temperature is called its ‘Specific Heat Capacity’ and is given the symbol c.
7
8
Calculations
• To calculate heat required we use:H - J m - kg C - J/kg/ ºC ∆T - ºC
H
= mcΔT
Constant Volume
•
If we increase the temperature of a gas in a container at a constant volume, the particles will move with more energy, and so there will be more collisions, and so greater pressure:Pressure increases with Temperature
Constant Pressure
•
If we increase the temperature of a gas in a container at a constant pressure, the particles will move with more energy, but they need more space to keep the collisions constant and so there will be a greater volume:Volume increases with Temperature
10
11
Constant Temperature
•
If we keep the temperature of a gas constant, we keep the kinetic energy of the particles constant.•
Decreasing the volume of the gas’ container will increase the number of collisions of the particles with the container.•
The pressure of the gas will increase.•
Pressure and Volume changes are described by the following relationship:P
1V
1= P
2V
2Brownian Motion
•
When pollen grains are placed on the surface of a liquid and a strong light source is used to illuminate the pollen, the pollen is seen to move randomly.•
This movement is called ‘Brownian Motion’ and cause by the invisible water particles hitting the pollen grains.Expansion
• When particles are heated they gain energy.
• They become more spaced-out, and the material gets bigger.
• We say that the material expands.
• Generally, objects expand as they get hotter and contract as they get cooler.
• Liquids expand more than solids on heating, and gases expand more than liquids.
• Solids expand with the greatest force. Gases expand with the least force.
13
14
Questions on Expansion
•
Why do walls have expansion joints?•
Why are pylon electrical cables tighter in winter?•
Why do railway lines leave regular gaps between them?Temperature Scales
•
The most common temperature scale that is used is the Celsius scale. This has its zero at the freezing point of water, and the boiling point of water is 100°C.•
In Physics, the Kelvin scale (or Absolute Temperature scale) is often used.•
This is often more sensible as the zero is defined as the point at which the particles have no kinetic energy (Absolute Zero).•
To convert between Celsius and Kelvin, we add 273°C.•
A rise of 1K is the same as a rise of 1°C.Internal Energy
•
The Kelvin Temperature is proportional to the average kinetic energy of the particles.16
17
Evaporation
•
Evaporation is a process by which a liquid cools due to the fact that particles are lost from its surface.•
The higher energy particles will be more likely to leave the liquid, so lowering the average KE of the particles remaining in the liquid. The temperature will thus belowered.
•
Increasing the exposed surface area of the liquid, or increasing the movement of air will increase the rate of evaporation.Changing State
When a material changes from one state to another, bonds are either broken or created. This involves an associated Internal Energy change.
When bonds are broken, heat must be supplied. When bonds are created, Heat is released.
Since the energy changes are entirely Internal, there is no change in kinetic energy of the particles, and hence no change in the temperature of the material.
Thermometry
To make a thermometer, we need a property that changes with temperature in a linear fashion. We then need to calibrate the thermometer by choosing two fixed points.
The fixed points for calibration are the boiling point of water (100°C) and the freezing point of water (0°C).
The scale is then divided into 100 equal parts for interpolation.
19
20
Liquid in Glass Thermometers
•
Liquid in glass thermometers have liquid in a glass bulb. As the liquid is heated it expands and its level rises up the scale.•
The choice of liquid, the thinness of the bore or the size of the bulb will affect the sensitivity of the thermometer.•
The choice of liquid will affect the range of the thermometer.Thermocouple
• A thermocouple is a junction of two different metals.• Electrons will move across the junction creating a measurable voltage.
• The higher the temperature, the more energy the electrons will have, more electrons will move and we get a greater voltage.
• The voltage is then calibrated.
• High temperatures can be quickly recorded.
