Collins
CSEC® PHYSICS
WORKBOOK
Terry David
.~I?!'R
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:J>O~
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Collins
HarperCollins Publishers
I London Bridge Street
London SE I 9GF
First edition 2015
1098765432
© HarperCollins Publishers Limited 2015
ISBN 978-0-00-81 1603-3
Collins®is a registered trademark of HarperCollins Publishers Limited
C5Ece Physics Workbook is an independent publication and has not been authorised, sponsored or otherwise
approved by CXC".
C5EC® is a registered trade mark of the Caribbean Examinations Council (CXC).
www.collins.co.ukfcaribbeanschools
A catalogue record for this book is available from the British Library
Typeset by QBS
All rights reserved . No part of this book may be reproduced, stored in a retrieval system , or transmitted in
any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior
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If any copyright holders have been omitted, please contact the Publisher who will make the necessary
arrangements at the first opportunity.
Author: Terry David
Illustrators: QBS
Publisher.: Elaine Higgleton
Commissioning Editor: Tom Hardy
Project Manager: Sarah Dev-Sherman for QBS
Managing Editor: Sarah Thomas
Editor: Niamh O'Carroll
Copy Editor: Cathryn Primrose-Mathisen
Proofreader: Carol Osborne
Contents List
Section A
Al
A2
A3
A4
AS
A6
Scientific method ............................................................ .................................... ... ........... .4
Vectors ................................................................................................................................. 8
Statics ........................................................ .................................................. ...................... 11
Dynamics .......................................................................................................................... 15
Energy .......................................................................................................... .................... 24
Hydrostatics ...................................................................................................................... 27
Section B
B1 Nature of heat ................................................................................................................... 32
B2 Macroscopic properties and phenomena ..................... ...... ........................................... 33
B3 Thermal measurements .................................................................................................. 39
B4 Transfer of thermal energy ....................................................... ..................................... 45
Section C
C1 Wave motion ................................................................................................. .. ................. 49
C2 Sound ................................................................................................................................ 52
C3 Electromagnetic waves .................................................................................................... 55
C4 Light waves ...................................................................................................................... 56
C5 Lenses ................................ ................................................................................................ 63
Section D
D 1 Electrostatics .............................................................................. .................. ... ................ 66
D2 Current electricity........................... ............................. .................................................... 69
D3 Electrical quantities ......................................................................................................... 72
D4 Circuit components ................................. .. .................................................... .................. 75
D5 Elec tronics ................................................................. ....................................................... 83
D6 Magnetism ............................................................................. .................... ...................... 86
D7 Electromagnetism ............................................................................................. .............. 88
Section E
E1 Models of the atom .................. .... ............ ....................................................................... 96
E2 Structure of the atom ...................................................................................................... 97
E3 Radioactivity ................................................................................................................. 100
3
Al l.
o
Scientific method
Anya performs an experiment to measure the acceleration due to gravity (g). The time
taken for 20 complete oscillations (t) was recorded as the length (I) of the pendulum
was varied. The results are shown in the table below:
Time taken for
20 oscillations tIs
Length lim
Period TIs
T'ls'
15·5
20·1
23·7
26·9
29·8
32-4
0·150
0-775
0·250
0·350
0·450
0·550
0·650
0·601
a) Complete the table above.
[6)
b) Plot a graph ofT' against 1. Use the graph paper on the page opposite.
[10)
c) Determine the slope S of the graph in b) and include its units.
[4)
d) Given that S = 39'4, determine the acceleration due to gravity g.
g
[2)
4
+
;
-t
-t
+-t
t
!,
.
-f
IT
t
H-
~
5
..
Scientific method (cont.)
o
Daniel wants to determine the density of steel. He measured the mass of ten steel
marbles. He measured the volume of the ten marbles by placing them in a measuring
cylinder filled with 50 em 3 of water.
His findings are listed below:
• mass of ten steel marbles = 336 g
• initial volume of water in measuring cylinder = 50 em'
• final volume of water in measuring cylinder = 92 em'
a) Explain what is meant by the term' density' and state its SI units.
[3]
b) State the mass of the one steel marble in kg.
[2]
c) State the volume of the one steel marble in m' .
[2]
d) Calculate the density of steel in kgm-'.
[3]
6
e) Calculate the relative density of steel, assuming that the density of water is
1000 kgm- 3 •
o
[31
Complete the following table.
Quantity being measured
1 Diameter of a wire
2 Mass of a coin
3 Temperature of boiling water
4 Electric current flowing in a circuit
5 Period of a pendulum
Instrument most suitable
[51
•
Two students are measuring the acceleration due to gravity g using a simple pendulum.
Student A measures the value as 8.9 ms-2 and Student B measures the value as 5 ms-2 •
a) State two possible errors in student B's experiment.
[21
b) It is known that the exact value of g = 9.81 ms-2 • Suggest how student A can improve
the accuracy of his experiment.
[11
<
Total Marks
7
/43
Vectors
o
a) Distinguish between a scalar and a vector quantity.
[3)
b) Give one example of a scalar quantity and one example of a vector quantity.
scalar quantity __________________________
[1)
vector quantity __________________________
[1)
c) 'The diagram below shows a force of 5 N acting on an object P at an angle of 30° to
the horizontal:
SN
p
By drawing appropriate lines on the diagram, use a ruler to determine:
i)
the horizontal component of the 5 N force.
[1)
ii) the vertical component of the 5 N force.
[1)
8
d) A heavy object of weight W is being held stationary by two ropes A and B.
The tension in each rope is T.
B
A
T
T
w
i)
Draw a vector diagram showing all THREE forces.
[3]
ii) Calculate the weight W of the heavy object if the tension T in each rope is 500 N.
[3]
9
Vectors (cont.)
o
An object 0 is acted upon by a 6 N force and a 5 N force. The angle between these two
forces is 60°.
a) Draw a scale diagram showing the forces acting on object 0 and determine the
resultant force.
[5]
b) Determine the angle between the resultant force and the 6 N force
[1]
<
10
Total Marks
119
Statics
o
a) Complete the following table relating to some fundamental quantities:
Fundamental
Mass
Len th
Time
Tern erature
SI unit
S mbol
metre
s
[6)
b) Work and power are defined as follows:
work = force x distance
power = ",:ork
time
i)
Determine the 51 unit of work in terms of base units.
[2)
ii) 5tate an alternative name for the 51 unit of work.
[1)
iii) Determine the 51 unit of power in terms of base units.
[2)
iv) 5tate an alternative name for the 51 unit of power.
[1)
11
Statics (cont.)
•
a) Explain what is meant by the 'moment' of a force, and state its SI unit.
[3]
b) State the principle of moments.
[3]
c) The diagram below shows a forearm holding a ball of weight 50 N horizontally.
The elbow is at point A and acts like a fulcrum. The weight of the forearm is 20 N
and is 14 cm away from the elbow. The bicep muscles exert an upward force X.
x
A
.+---+
4cm
14cm
B
20 N
i)
16cm
50 N
Use the principle of moments to calculate the force X exerted by the bicep
muscles.
[4]
12
ii) A downward force Y is exerted at point A. Calculate this force.
o
[3]
A Form Four student is investigating Hooke's law. She attaches various masses to a
spring of length 80 em and measures the extension produced. She obtains the following
data:
Massi
Wei ht/N
Extension/em
10
30
50
80
100
150
180
200
0·4
1·2
2·0
3·2
4·0
6·0
7-2
8·0
a) Complete the table. (g = 10 Nkg- l )
[4]
b) Plot a graph of extension (y-axis) against weight (x-axis). Use the graph paper
on the next page.
[10]
e) From your graph, calculate the slope S.
[3]
d) The spring constant is related to the slope of the graph as follows:
.
1
spnng constant = S
Calculate the spring constant and state its units.
[3]
13
Statics «(ont.)
e) By drawing suitable lines on your graph, estimate:
i)
the mass that was attached to the spring to produce a TOTAL length of 85·2 cm.
[3]
ii) the extension of the spring when a mass of 60 g is attached to it.
[3]
, .
'+
'+
+
t
!
<
14
Total Marks
•
/51
Dynamics
o
a) Define EACH of the following and state the SI unit in which EACH is measured:
i)
velocity.
[21
ii) acceleration.
[2]
b) A ship of mass 3·0 x 107 kg is initially travelling at a constant speed of 12 ms-'.
As it approaches land, its engines are turned off. It decelerates uniformly and comes
to rest in 30 minutes.
i)
Sketch a velocity-time graph to illustrate the motion of the ship.
[3]
ii) Calculate the deceleration of the ship.
[3]
1S
"~ A4 ~
.,'
..
Dynamics (cont.)
·l
iii) Calculate the distance travelled by the ship in 30 minutes.
[3]
iv) Calculate the magnitude of the force acting on the ship as it slows down.
o
[3]
Aristotle and Newton had different views about the relationship between force
and motion.
a) State Newton's second law of motion.
[3]
b) Describe Aristotle's idea about the relationship between force and motion.
[3]
16
c) State what Aristotle and Newton would say about the forces acting on a car in EACH
of the following scenarios:
i)
a stationary car of mass m.
Aristotle
[1]
Newton
[1]
ii) a car of mass m travelling at a constant speed v.
Aristotle
[1]
Newton
[1]
iii) a car of mass m travelling at a lower constant speed f.
Aristotle
[1]
Newton
o
[1]
a) Explain what is meant by EACH of the following terms:
i)
linear momentum.
[2]
ii) the law of conservation of linear momentum.
[3]
17
•
Dynamics (cont.)
b) Two cars of equal mass are travelling at the same speed towards each other.
They collide in a head-on collision and they both come to rest. Explain how the
law of conservation of momentum applies in this collision.
[4]
c) A projectile of mass 0·12 kg is fired at a stationary block of wood of mass 4·5 kg.
The projectile embeds itself in the block of wood and they both move off with
a velocity of 4·2 ms- I • Calculate the velocity of the projectile just before striking
the block of wood.
o
[4]
a) i)
Distinguish between displacement and distance travelled.
[2]
ii) Explain how it is possible for a car to travel a distance of 100 m, yet have zero
displacement.
(Hint: providing a diagram will help.)
[3]
18
. b) A car has a mass of 500 kg. The velocity-time graph of its journey along a straight
road is shown below:
velocity/ms-1
20
o
i)
120
500
850
tis
Calculate the acceleration during the first 120 seconds.
[3]
ii) Calculate the force required to produce this acceleration.
[3]
iii) Calculate the distance travelled in 850 seconds.
[3]
iv) Calculate the average speed for the entire journey.
[3]
19
Dynamics (cont.)
v) Calculate the linear momentum of the car at 200 seconds.
[3]
•
a) State Newton's THREE laws of motion.
first law
[2]
second law
[2]
third law
[2]
b) Distinguish between a body's mass and its weight.
[2]
20
- c) Define the unit of force.
[2]
d) State the nature of the unbalanced force acting in EACH scenario below:
i)
the moon orbiting the earth.
[1]
ii) a stone attached to a string travelling along a circular path.
[1]
iii) a car travelling around a bend.
[1]
e) Telecommunication satellites orbit the earth. They allow for voice, data and video
signals to be transmitted across the globe.
i)
Explain how this circular motion is maintained.
[4]
ii) Explain how Newton's third law applies.
[3]
21
A4
o
·~
Dynamics (cont.)
A boy throws a ball of mass 0·01 kg vertically upwards with a speed of 12 ms- I .
acceleration due to gravity, g = 10 ms- 2
a) Calculate the initial momentum of the ball.
[3]
b) Calculate the time taken for the ball to reach a maximum height.
[3]
c) The boy catches the ball. Sketch a velocity-time graph to illustrate the motion
of the ball.
[3]
22
d) State how you would find the maximum height reached by the ball from the
velocity-time graph.
[1)
e) Determine the maximum vertical height reached by the ball.
o
[2)
A ball is thrown horizontally from a table at a speed of2 ms-I . The ball falls for
3 seconds. [Acceleration due to gravity g = 10 ms-')
Determine
a) The horizontal component of the ball's velocity at time 3 seconds.
[1)
b) The vertical component of the ball's velocity at time 3 seconds.
[3)
<
23
Total Marks . .
/97
Energy
o
a) i)
Explain what is meant by the term 'energy'.
[1]
ii) Explain what is meant by the 'law of conservation of energy'.
[3]
b) State the main energy changes occurring in EACH of the following processes:
i)
turning on a light bulb.
[3]
ii) a mango falling from a branch of a tree.
[3]
iii) a gasoline-operated car travelling along a straight road.
[3]
24
c) An engineer at NASA is investigating the impact of meteorites on planets.
He performs experiments in a vacuum by dropping metal spheres of different
sizes and different heights above a horizontal bed of sand. In one experiment, a
metal sphere of mass 0·1 kg is dropped from a height of 1·2 m. The sphere makes a
depression in the sand of 2 cm.
gravitational field strength, g = 10 Nkg-'
i)
Calculate the potential energy of the sphere at a height of 1·2 m.
[31
ii) Calculate the velocity of the sphere just before hitting the surface of the sand.
[3)
iii) Calculate the average retarding force acting on the sphere as it comes to rest in
the sand.
[3)
G Brandon is loading boxes onto the tray of a flatbed truck. He uses a ramp of length 8 m
to assist him. He pushes a box of mass 120 kg up the ramp with a force of 200 N.
The box moves through a vertical distance of 0·8 m.
gravitational field strength, g = 10 Nkg-'
2S
•
Energy «(ont.)
a) What is meant by the term 'work'?
[1]
b) Calculate the change in gravitational potential energy of the box.
[3]
c) Calculate the work done by the 200 N force.
[3]
d) Explain why the answers to b) and c) are different.
[3]
e) Calculate the efficiency of the ramp.
[3]
< Total Marks
26
/35
Hydrostatics
o
a) Explain what is meant by the term 'pressure'.
(2)
b) State the SI unit of pressure.
[1 )
c) State TWO instruments used to measure pressure.
(2)
d) A cyclist and his bicycle have a combined mass of 55 kg. The total area of the tyres in
contact with the road is 2·2 x 10- 3 m'. Calculate the pressure exerted on the ground.
gravitational field strength, g = 10 Nkg- I
(5)
•
A scuba diver is at a depth of 45 m below the surface of the sea. The density of seawater
throughout the water column above the scuba diver is 1150 kgm- 3•
atmospheric pressure = 100 kPa
Calculate:
a) the pressure acting on the scuba diver due to the seawater only.
(3)
27
Hydrostatics (cont.)
b) the total pressure acting on the scuba diver.
o
[21
a) State Archimedes' principle.
[21
b) An oil drum is floating vertically on water as shown below:
water
surface
i
1
0-75 m
I
.
. -- ---
.
I
I
gravitational field strength, g = 10 Nkg-', density of water
atmospheric pressure = 1 x 105 Pa
i)
= 1000 kgm-"
Calculate the volume of water displaced.
[31
28
ii) Calculate the mass of the water displaced.
[3]
iii) Calculate the upthrust acting on the oil drum.
[3]
iv) State the weight of the oil drum.
[1]
v) Calculate pressure at a depth of 0·75 m below the surface of the water.
o
[4]
A cylindrical block has a length of 0·18 m, a uniform cross-sectional area of
3·8 x 10-4 m' and a density of 1250 kgm-3• The block is suspended from a spring
balance and fully immersed in a liquid with a density of 750 kgm-3 •
a) Calculate the mass of the block.
[3]
29
Hydrostatics (cont.)
b) Calculate the weight of the block.
[21
c) Calculate the upthrust on the block when it is fully immersed in the liquid.
[41
d) Determine the reading on the spring balance.
o
[21
The diagram below shows a simple braking system in a vehicle:
Brake pedal
B
Brake fluid
30
When a driver pushes the brake pedal, a force FI is exerted over an area Al in the
master cylinder A. The cross-sectional area of cylinder B is A,. A force F, is then
applied to the braking mechanism in the wheels of the vehicle.
FI
= 150 N, Al = 2·0 em', A, = 3·0 em'
a) Calculate the pressure exerted in cylinder A in pascals.
[3)
b) State the pressure exerted in cylinder B.
[1)
c) Calculate the force F"
[3)
<
31
Total Marks
__
/49
Nature of heat
o
a) Briefly outline the caloric theory about the nature of heat.
[4]
b) Briefly discuss the weakness with the caloric theory.
[2]
c) Rumford conducted an experiment that provided evidence against the caloric theory.
i)
Briefly outline this experiment.
[3]
ii) Describe the main conclusion and explain why it does not support the caloric theory.
[3]
<
32
Total Marks
112
Macroscopic properties and phenomena
o
a) State TWO physical properties that can be used as a basis for measuring temperature.
[2]
b) Define the lower fixed point and the upper fixed point on the Celsius scale of
temperature, and state their values in degrees Celsius.
i)
lower fixed point
[21
ii) upper fixed point
[21
c) A liquid-in-glass thermometer is commonly used in a physics laboratory.
State TWO advantages of using mercury as the liquid in this type of thermometer.
[21
d) A thermocouple is another type of thermometer. State TWO advantages of this type
of thermometer over a mercury-in-glass thermometer.
[21
33
Macroscopic properties and phenomena
(cont.)
o
a) State TWO main assumptions of the kinetic theory of gases.
[2]
b) Use the kinetic theory of gases to explain the following:
i)
a gas exerts a pressure on the walls of the container in which it is stored.
[5]
ii) the pressure of a gas inside a metal container increases as the temperature of the
container increases.
[4]
34
o
o
A bimetallic strip consisting of copper and iron is found inside an electric iron.
Use a sketch to explain how it can be used to regulate the temperature of an electric iron.
[4]
a) State Charles's law.
[21
b) A physics student is investigating the relationship between the volume of a fixed
mass of gas and its temperature, at a constant pressure of 1 atmosphere.
Tern erature/"C
Volume/cm 3
l
30
50·6
60
55·6
35
no
64·0
--,-----,
160
72-3
210
80·7
260
89·0
J
Macroscopic properties and phenomena
(cont.)
Using a diagram, explain how the student could perform this experiment in a
physics laboratory.
[5]
c) Plot a graph of the volume of the gas in b) (y-axis) against its temperature (x-axis).
(Use a range of -300°C to 300°C on the x-axis.)
[9]
'r--I
+- - r+
•
t--+·
T·
.~
-I-
t
-+ •
+
36
t
•
f-
t
d) From the graph, determine the volume when the temperature is -100°C.
[1]
e) From the graph, determine the temperature when the volume is zero.
[1]
f) Comment on the significance of this temperature.
[1]
g) Determine the gradient of your straight line and state its units.
[4]
4) a) State Boyle's law.
[2]
b) State the pressure law.
[2]
37
Macroscopic properties and phenomena
(cont.)
c) A car tyre is inflated with air. The initial temperature of the air and the pressure
inside the tyre are 27°C and 190 kPa respectively. The car travels from point A to
point B and the temperature of the air inside the tyre increases to 67°C.
Assuming that the tyre does not expand, calculate the new pressure inside the tyre.
[5]
d) The driver of the car in c) gets a flat tyre at point B. He replaces the tyre.
The initial temperature of the air and the pressure inside the tyre are 27°C and
190 kPa respectively. The car travels from point B to point A and the temperature of
the air increases to 67°C. Assuming that the tyre expands by 5%, calculate the new
pressure inside the tyre.
[6]
<
38
Total Marks
/63
Thermal measurements
o
Yashoda prepares some lime juice on a hot day. She adds 80 g of ice at a temperature
of 0 °C to 0·32 kg of lime juice. The temperature of the lime juice decreases from 29°C
to 8 °C and all the ice melts.
latent heat of fusion of ice = 3·4 x 10 5 Jkg-I, specific heat capacity of
water = 4·2 x 103 Jkg- IO C 1
Calculate:
a) the energy required to melt 80 g of ice.
[3]
b) the energy gained by the melted ice.
[3]
c) the energy lost by the lime juice.
[2]
d) the specific heat capacity of the lime juice.
[3]
39
Thermal measurements (cont.)
o
An engineer demonstrates how a solar cooker can be used to cook food in a rural area
of Trinidad. It consists of a parabolic reflector of surface area 4·0 m' . The solar power
incident on it is 850 Wm-'. 65% of the energy incident on the reflector is absorbed
by the pot containing the food. After 40 minutes, the temperature of the pot and its
contents increases by 75°C. The heat capacity of the pot and its contents is 8200 JOCI.
Calculate:
a) the energy incident on the parabolic reflector every second.
[3)
b) the energy absorbed by the pot and its contents in 40 minutes.
[3)
c) the energy required to raise the temperature of the pot and its contents by 75°C.
[3)
d) the efficiency of the solar cooker.
[3)
40
o
a) Distinguish between the process of evaporation and that of boiling.
(4)
b) When a volatile liquid evaporates, the temperature of the remaining liquid
decreases. Explain this using the kinetic theory.
(4)
•
a) Explain what is meant by the terms 'specific heat capacity' and 'heat capacity'.
(4)
b) State an equation that relates these two quantities.
(1)
c) Define the term 'latent heat of fusion'.
(3)
l
41
Thermal measurements (cont.)
d) An electric heater is placed into an insulated container filled with 150 g of crushed
ice at -10°C. The heater is switched on for 690 seconds. All the ice is converted into
water at 25°C.
specific heat capacity of ice 2·0 Jg-IO C- 1
specific heat capacity of water 4·2 Jg-IOC-l
Calculate:
i)
the energy required to increase the temperature of 150 g of the ice from - 10 °C
to 0 0C.
(3)
ii) the energy required to convert 150 g of the ice at 0 °C into 150 g of water at 0 0C.
(3)
iii) the energy required to increase the temperature of the water from 0 °C to 25°C.
(3)
iv) the power rating of the heater, assuming heating at a constant rate.
(3)
42
o
You are required to measure the specific heat capacity of a cylindrical block of copper
using an electrical method.
a) List the apparatus required to perform this experiment.
[5]
b) Draw a diagram of the circuit you would use in this experiment.
[3]
c) Briefly explain the measurements required and show how the specific heat capacity
is calculated.
[4]
d) State TWO precautions taken in order to improve the accuracy of the results.
[2]
43
Thermal measurements (cont.)
o
You are required to measure the specific latent heat of fusion of ice using an electrical
method.
a) List the apparatus required to perform this experiment.
(5)
b) Draw a diagram of the circuit you would use in this experiment.
(3)
c) Briefly explain the measurements required and show how the specific latent heat of
fusion is calculated.
(4)
< Total Marks ..... ...
44
..... /77
Transfer of thermal energy
o
a) State the THREE methods by which thermal energy is transferred.
[3]
b) Hamlet uses a vacuum flask to store his hot soup for lunch. Choose THREE design
features of a vacuum flask and explain how they minimise thermal energy losses by
the methods in a).
[6]
. , a) Solar water heaters are used extensively in Barbados. The diagram below shows the
construction of a particular solar water heater:
Storage
tank
Glass
Cold water
Blackened surface
' - - - i - --------- To home
Hot water
45
Transfer ofthermal energy (cont.)
Explain the reason for using EACH of the following:
copper tubes. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
blackened surface. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
glass. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
[3]
b) Explain the greenhouse effect.
[3]
c) Explain why there is growing concern among scientists and policymakers to reduce
the amount of carbon dioxide emission from industries.
o
[3]
Explain what is meant by EACH of the following terms:
a) conduction.
[2]
46
b) convection.
[2]
c) radiation.
o
[2]
a) Thermal energy reaches the earth from the sun by one of the three methods of
thermal energy transfer. State the method and explain why the other two are not
applicable.
[3]
b) Sketch a simple diagram to explain how the direction of sea breezes is determined.
[3]
47
Transfer of thermal energy (cont.)
c) Two similar metal containers A and B are filled with water and placed side by side
in sunlight. Container A is painted silver on the outside and container B is painted
black on the outside. After hour the temperature of the water in one of the
containers is higher than the other.
+
i)
State which container contained the water at the higher temperature.
[1)
ii) Explain your answer to c) i).
[1)
d) Two similar metal containers A and B are filled with boiling water and placed side
by side on a table. Container A is painted silver on the outside and container B is
painted black on the outside. After hour the temperature of the water in one of the
containers is lower than the other.
+
i)
State which container contained the water at the higher temperature.
[1)
ii) Explain your answer to d) i).
[1)
e) Complete the statement.
Good absorbers are also __________________ of radiation.
[1)
<
48
Total Marks
. /35
Wave motion
o
a) Explain what is meant by the following terms:
i)
wavelength.
[1]
ii) frequency.
[1]
iii) amplitude.
[1]
b) The diagram below shows the displacement-time graph of a transverse wave:
Displacement/em
0-8
O~-+r
0-8
tis
- 0'8
Determine:
i)
the amplitude of the wave.
[1]
49
Wave motion (cont.)
ii) the frequency of the wave.
[3]
iii) the speed of the wave if its wavelength is 1·5 cm.
o
[3]
a) Explain what is meant by the following terms:
i)
a progressive wave.
[2]
ii) a transverse wave.
[2]
iii) a longitudinal wave.
[2]
50
b) Give an example of EACH type of wave in a).
a progressive wave _ _ _ _ _ _ _ _---'-_ _ _ __ _ _ _ _ _ _ _ _ __
a transverse wave _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
a longitudinal wave _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
o
[3]
The period of a wave is 20 ms and its wavelength is 4 cm. Calculate
a) The frequency of the wave.
[3]
b) The velocity of the wave.
[3]
<
51
Total Marks
_ /25
Sound
o
a) Describe a simple experiment to measure the speed of sound in air.
[5]
b) A loudspeaker produces a sound with frequency 250 Hz. Assuming the speed
of sound is 340 ms- J, determine the wavelength of the sound waves.
[3]
c) A tropical storm approaches Jamaica. Ingrid measures the time between seeing a
flash of lightning and hearing the sound of thunder. She estimates it to be 9 seconds.
Calculate the distance between the tropical storm and Ingrid.
o
[3]
a) Sound is a longitudinal wave. What does this mean?
[2]
52
b) The pitch and loudness of a sound is related to certain wave parameters.
State what EACH one is related to.
pitch _ _ _ _ __ _ _ _ _ _ __ _ __ _ _ _ _ _ _ _ _ _ __
loudness _________________________________________________________
[2]
c) State THREE differences between sound waves and light waves.
[3]
d) State the range of frequencies that can be detected by a young adult's ear.
o
[2]
a) Saleema has a radio playing in her living room. The room has one door of width
0·9 m. She is cooking in her kitchen. Explain why she is able to hear the sound of
the radio in the kitchen even though she cannot see the radio.
[4]
b) A signal generator is connected to two loudspeakers in a physics laboratory as shown
below. Riaz, a Form Four student, starts at point P and walks along the line AB.
Signal
generator
A
p
B
•
53
Sound (cont.)
i)
State what he hears as he walks along the line AB.
[2]
ii) State what wave phenomenon is being observed.
[1]
iii) Explain the observations using the wave phenomenon stated in b) ii).
o
[5]
Sound waves have many useful applications. In Trinidad, engineers use sound waves
to conduct seismic surveys. They are able to produce pictures of geological formations
below the earth's surface. This helps them to find crude oil. Describe TWO other
applications of sound waves, one in each of the following areas:
medicine. ___________________________________________________________
industr~[4]
<
54
Total Marks
/36
Electromagnetic waves
o
a) State FOUR properties of electromagnetic waves.
[4]
b) Microwaves, visible light and infrared radiation are all electromagnetic waves.
Arrange them in ascending order of wavelength.
[3]
c) Microwaves travelling at 3 x 108 ms- I have a frequency of2 x 10 10 Hz. Determine the
wavelength of these waves in em.
[3]
d) Complete the following table:
Electromagnetic wave
Source
Use
infrared radiation
x-rays
microwaves
cellular phone
photosynthesis
visible light
[6]
< Total Marks .
55
........ ... /16
Light waves
o
a) In the 17th century there were two conflicting theories about the nature of light.
Huygens proposed one of these theories and Newton supported the other.
Briefly outline these TWO theories.
Newton _______________________________________________________
Huygens _______________________________________________________
[2]
b) Young provided experimental evidence that supported one of the theories in a).
Which one did it support?
[1]
c) Einstein used one of the theories in a) to explain the observations of experiments in
which light was interacting with matter. Which one was it?
o
[1]
a) Explain what is meant by the term 'diffraction'.
[1]
b) Light is usually thought of as travelling in straight lines because diffraction is not
normally observed. State why this is so and state ONE observation that supports this.
[2]
56
c) Draw two diagrams to show the diffraction of waves through a narrow gap and a
wide gap.
[6]
d) What can be said about the wavelength of a wave before and after it passes through
a gap?
[1]
e) Under what conditions do waves show the most diffraction?
o
[1]
a) State the laws of reflection.
[2]
b) The diagram below shows an object 0 in front of a plane mirror. Two rays oflight R
and R, are shown. Complete the path taken by the two rays and locate the image O.
o
j
[4]
o
a) Explain what is meant by the 'refraction' of light.
[2]
57
Light waves (cont.)
b) In terms of the wave theory, explain why the refraction of light occurs.
[31
c) A ray of light strikes a glass block at an angle of 60° as shown below. The refractive
index of glass is 1·50.
Glass
Air
i)
Calculate the angle of refraction as the light enters the glass block.
[31
ii) Calculate the critical angle for the glass in this block.
[31
58
iii) On the diagram, complete the path of the ray of light until it leaves the glass
block, and indicate the angle of incidence each time the ray strikes a glass-air
boundary.
o
[4]
a) Explain what is meant by the following terms:
i)
refractive index.
[2]
ii) critical angle.
[2]
iii) total internal reflection.
[2]
b) The critical angle for glass is 42°. Fibre optic cables make use of total internal
reflection and are used to transmit data at the speed of light. Use a diagram to
illustrate how very thin glass fibres are able to transmit light pulses.
[3]
c) State another application of total internal reflection.
[2]
59
;~· C· ~ i!· .
,r··
...
Light waves (cont.)
.'
o
a) Thomas Young performed an experiment to demonstrate that light can produce an
interference pattern. Using a diagram, outline Young's double slit experiment.
[5)
b) State what was observed in this experiment.
[1)
c) Explain the observations as fully as you can.
[6)
d) Explain the role of diffraction in this experiment.
[2)
60
o
a) The velocity oflight in air is 3·0 x 108 ms- I. The velocity oflight in glass is
1·9 x 108 ms-I. Calculate the refractive index of glass.
[3)
b) Light has a wavelength of 1·2 x 10-6 m in air. Calculate the frequency of light in air.
[3)
c) Calculate the wavelength of light in glass.
[3)
d) A ray of light is travelling from glass into air. The angle of incidence is 30°..
Calculate the angle of refraction.
[3)
e) Explain why refraction occurs when light travels from air to glass.
[2)
61
Light waves (cont.)
f) Sketch a diagram to show how a triangular glass prism can be used to produce a
spectrum. Indicate the position of the red and violet colours.
o
[3]
The refractive index of water is 1·33. A lamp is installed at the bottom of a swimming
pool. The diagram below shows THREE rays leaving the lamp:
Air
2
---+-Water
3
a) Calculate the critical angle of water.
[3]
b) Calculate the angle of refraction for ray 2.
[3]
c) Complete the path of rays 1, 2 and 3 on the diagram.
[3]
<
62
Total Marks
. /87
Lenses
o
a) Eddy uses a converging lens as a magnifying glass to view fine print on an
instruction manual. Sketch a diagram to show the image formed.
Label the principal axis and the focal point of the converging lens.
[4]
b) State whether the image is virtual or real.
o
[1]
An object of height 2·5 cm is placed 12 cm in front of a converging lens. An image is
produced 4 cm behind the lens. Using the lens formula, calculate:
a) the focal length of the lens.
[3]
b) the magnification of the lens.
[3]
63
Lenses (cont.)
c) the height of the image.
o
[3]
Use a diagram to explain what is meant by the following terms when applied to a
converging lens:
focal point; focal length; principal axis; optical centre.
[4]
•
a) A converging lens has a focal length of 8·0 cm. An object of height 4·0 cm is placed
12·0 cm in front of the lens. Using the graph paper on the next page, determine by
scale drawing:
i)
the image distance.
[1]
ii) the height of the image.
[1]
iii) the magnification of the lens.
[1]
b) State ONE use of this type oflens.
[1]
64
.l-
-H
IT
-t·i~r:;
tHH
.:-
t-!
H
;
,8:
·1
+,
I ;..
-r
~-
1"":
-I.
H·
. if
H
H
p:
+
1-
h
-H
t
. f
1H
f.i
+-t - t
,-
+
+-
H
f+
t-!± -.:j:i
T
.f=::
.
,
<
65
Total Marks _
. ..... /22
Electrostatics
o
a) When a polythene rod is rubbed with a dry cloth it becomes negatively charged.
Explain, in terms of electron flow, why this occurs.
[3]
b) When a Perspex rod is rubbed with a dry cloth it becomes positively charged.
Explain, in terms of electron flow, why this occurs.
[3]
c) Saishma demonstrates a 'trick' to her friends. She rubs a pen against her hair and
then uses it to pick up small pieces of paper. Explain how the pen is able to pick up
the uncharged pieces of paper.
[4]
d) A positively charged metal sphere A rests on an insulated stand. A negatively
charged metal sphere B rests on an insulated stand. A thick piece of copper wire is
used to connect both spheres. A current of 4 f.lA flows for 2 ms.
66
i)
State the direction of electron flow between the two spheres.
[1]
ii) Calculate the amount of charge that flows between the two spheres.
[3]
iii) Calculate the number of electrons that were transferred between the two spheres.
charge on an electron = -1·6 x
lO- 19
C
[3]
•
a) Explain what is meant by an 'electric field'.
[2]
b) Sketch the electric field for EACH of the following:
i)
an isolated positive charge. _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ __ _
[3]
67
Electrostatics (cont.)
ii) an isolated negative charge. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
[31
8
iii) a positive charge adjacent to a negative charge. _ _ _ _ _ _ _ _ _ _ __
[31
G
8
iv) a positive charge adjacent to another positive charge. _ _ _ _ _ _ _ _ __
[31
v) two parallel metal plates. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
[31
+
c) State ONE hazard and ONE useful application of electrostatics.
hazard _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
use _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___
[21
<
68
Total Marks
/36
Current electricity
o
a) Distinguish between a conductor and an insulator.
[2]
b) You are provided with the following:
an iron nail; a plastic spoon; a graphite rod; a piece of rubber.
Classify them as conductors and insulators.
conductors ________________________________________________________
[2]
insulators _________________________________________________________
[2]
c) Draw a simple circuit diagram to show how you can distinguish between the
conductors and insulators in b).
o
[4]
a) Explain what is meant by an 'electric current'.
[2]
b) State the SI unit of current.
[2]
69
Current electricity (cont.)
c) State the charge carriers in EACH of the following:
a copper wire. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
[1)
a sodium chloride solution. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
o
[2)
An electric current of2·5 rnA flows through a point P in a circuit for 2 minutes.
a) Calculate the total charge passing through the point P in 2 minutes.
[3)
b) The charge on an electron is -1·6 x 10-19 C. Calculate the number of electrons
passing the point P in 2 minutes.
[3)
•
a) Explain the difference between alternating currents (AC) and direct currents (DC).
[2)
b) For EACH of the following current-time graphs, state the type of current shown:
i)
[1)
70
ii)
[1)
iii)
[1)
o
The diagram below shows an electric current:
If A
2·S - --
40
Ums
-2·S ---- - ------
a) State the period and the peak value of the current.
[2)
b) Calculate the frequency of this current.
[3)
<
Total Marks .......
71
/33
Electrical quantities
o
a) Explain what is meant by the 'potential difference' across a conductor.
[2]
b) State the S1 unit of potential difference.
[1]
c) The current flowing through a heating element is 8·0 A when connected to a 220 V
supply. Calculate the power rating of this element.
[3]
d) A 220 V mains supply provides 650 W of power to an electrical device.
i)
Calculate the current supplied by the mains to the electrical device.
[3]
ii) Calculate the energy supplied to the electrical device in 5 minutes.
[3]
72
o
An electric motor is connected to a 6·0 V supply. It draws a current of 0·4 A and lifts a
0·6 kg mass through a distance of 1·5 m in 20 seconds.
gravitational field strength, g = 10 Nkg- I
a) Calculate the power supplied to the motor.
(3)
b) Calculate the work done in raising the mass.
(3)
c) Calculate the power output of the motor.
(3)
d) Calculate the efficiency of the motor.
(3)
73
Electrical quantities (cont.)
o
A filament lamp is connected to a power supply. A current of 0·1 A flows through it for
a period of 20 seconds. The energy dissipated in the lamp is 240 J.
a) Calculate the charge passing through the lamp in 20 seconds.
[3]
b) Calculate the potential difference across the lamp.
[3]
< Total Marks _____ _ __
74
/30
Circuit components
o
a) Draw a labelled diagram of a dry cell.
[4)
b) Draw a labelled circuit diagram to show how a car battery can be recharged.
[4)
c) Compare the characteristics of a zinc-carbon primary cell with a lead-acid battery.
Lead-acid batte
Terminal volta e
Maximum current
Internal resistance
Portabilit
[10)
7S
Circuit components (cont.)
. , Christmas tree lights are connected in a series and a parallel arrangement. Four lights
are connected in series and are called string A. Another four lights are connected in
series and are called string B. String A and string B are connected in parallel.
a) Sketch a circuit diagram showing both strings oflights.
[3)
b) If string A alone is connected to a power supply, explain what would happen if one
bulb were to blow.
[1)
c) A power supply is connected across the parallel arrangement of string A and
string B. Explain what would happen if one bulb is blown in string B.
[2)
76
o
Melissa is asked to investigate the relationship between the potential difference across
a conductor and the current flowing through it. She sets up a circuit in the Form Five
physics laboratory and obtains the following data:
VIV
2·50
3·50
4·50
5·50
6·50
7·50
8·50
9·50
limA
5·0
7·2
9-4
11·1
12·0
15·0
17·0
19·1
a) Plot a graph of V against 1.
[81
t
~t-
+1+
··fI· ,.f-;
::j:.
.
~+iT'
•
•~
t· ... :.
t -; . H
77
Circuit components (cont.)
b) Determine the slope S of the line and hence state the resistance of the conductor.
[41
c) Using a circuit diagram, explain how Melissa would have obtained the data in a).
[81
78
•
Three resistors are connected to a 4·5 V DC supply as shown below:
4.5 V
50
100
A
c
B
50
a) Calculate the effective resistance between Band C.
[4]
b) Calculate the effective resistance between A and C.
[3]
c) Calculate the current flowing through the 10 n resistor.
[3]
79
Circuit components (cont.)
d) Calculate the potential difference across the 10 n resistor.
(3)
e) The current flowing through EACH 5 n resistor is the same. Calculate this current.
(3)
•
Explain the reasons for the following:
a) an ammeter should have a very small resistance.
(3)
b) a voltmeter should have a very large resistance.
o
(3)
Electrical appliances in a home are usually connected in parallel to the main
electricity supply.
a) Give TWO advantages of connecting appliances in parallel.
(2)
80
b) A refrigerator has a three-pin plug attached to it. State the names of the wires
connected to EACH pin.
(3)
c) A refrigerator plug has a fuse inside of it. Explain the purpose of the fuse and state
which wire it is usually connected to.
(3)
d) The manufacturer of the refrigerator indicates that an earth connection is
mandatory. Explain why this is so.
(2)
e) An electric iron is rated at 1100 W. A television is rated at 120 W. These two
electrical appliances are connected in parallel with the 120 V AC electricity supply.
Each device has its own fuse.
i)
Calculate the current drawn by the electric iron.
(3)
ii) Calculate the current drawn by the television.
(3)
81
Circuit components (cont.)
iii) You are provided with the following fuses: 1 A; 2 A; 3 A; 9 A; 10 A.
Select an appropriate fuse for EACH appliance.
electric iron _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
television _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
(2)
f) The power company in Barbados issues an advisory indicating that homeowners
should unplug their appliances because the power supply in their area is fluctuating.
Explain why the power company made such a suggestion.
o
(3)
a) Sketch the I-V characteristics for a filament lamp and a semiconductor diode.
(6)
b) State how the resistance of a filament lamp changes as current increases.
(1)
<
Total Marks
82
__________ /94
Electronics
o
a) Draw a circuit symbol for EACH of the following logic gates:
Logic gate
Symbol
NOT
AND
NOR
[3]
b) Complete truth tables to show the function of EACH of the following:
AND gate
A
NOR gate
A
B
B
[6]
c) Complete the truth table for the following logic circuit:
A
B
E
A
B
0
0
1
1
0
1
0
1
C
D
E
[12]
83
Electronics (cont.)
o
a) A student wishes to rectify an alternating current using a single semiconductor
diode. For EACH of the circuits below, sketch the voltage-time graph across the
terminals AB.
i)
~".
f
::
[2)
ii)
j
v
IV
v
load
r-----B
1
iii)
r-----A
f
[2)
v
[2)
b) What is the similarity between ii) and iii)?
o
[1)
The circuit below is used to sound an alarm when a particular set of conditions occurs
inside a chemical plant:
A-----j
x
(---1
y
8-----1
84
z
Alarm
A, Band C are connected to the following sensors:
A
Temperature sensor
Pressure sensor
Flow rate sensor
B
C
The logic is assigned as follows:
Sensor
A
0
Temperature is less than 500°C
Pressure is less than 200 kPa
Flow rate is less than 10 m 3s- 1
B
C
1
Temperature is greater than 500 °C
Pressure is greater than 200 kPa
Flow rate is greater than 10 m 3s- 1
a) Analyse the circuit and complete the truth table:
A
B
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
x
C
0
0
0
0
1
1
1
1
y
z
[2]
b) State in words the conditions under which the alarm will sound.
[2]
•
Briefly discuss the impact of electronic and technological advances on society.
[3]
<
Total Marks __
85
/35
Magnetism
o
a) Differentiate between a magnetic and non-magnetic material.
[2]
b) Explain how a magnet is able to attract a non-magnetic object like a paper clip.
[2]
c) State the materials used to make EACH of the following:
permanent magnet. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
[2]
temporary magnet. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
o
[2]
a) Explain what is meant by a 'magnetic field'.
[2]
b) State how the direction of a magnetic field is defined.
[2]
86
c) Sketch the magnetic field around EACH of the following:
i)
[2]
ii)
[2]
iii)
[2]
<
87
Total Marks .
_ 118
Electromagnetism
o
a) Draw a labelled diagram of a step-up transformer.
[4]
b) A step-up transformer is designed to be as efficient as possible. State THREE design
features that make a transformer efficient.
[3]
c) A transformer consists of two coils wrapped around an iron core. The two coils are
not electrically linked.
Explain how a transformer works.
[4]
88
d) A step-up transformer is connected to a 120 V mains supply. The step-up
transformer is assumed to be 100% efficient and has an output voltage of 1·2 kV.
i)
The number of turns in the primary coil is 200. Calculate the number of turns in
the secondary coil.
[3]
ii) A load is connected to the secondary coil and the current drawn is 0·4 A.
Calculate the current flowing in the primary coil.
[3]
iii) Explain why electricity is distributed over long distances as AC at high voltage.
[3]
•
The diagram below shows a simple AC generator:
p
5
sn
89
· D7
~
Electromagnetism (cont.)
a) Identify the components P, Q and R.
P __________________________________________________
Q------------------------------------------- R__________________________________________________
[3]
b) The output of the AC generator is connected to a 5 n resistor. P is rotating in a
clockwise direction. Draw an arrow on the diagram on the previous page to indicate
the direction of the current flowing through the resistor.
[1]
c) Explain why a current flows in the resistor.
[3]
d) The peak output voltage from this AC generator is 15 V. Calculate the peak current
flowing through the resistor.
[3]
90
e) p is rotating at a rate of 20 revolutions per second. Sketch a graph showing the
variation with time of the current flowing through the resistor.
[5]
f) State TWO ways of increasing the magnitude of the current flowing in the resistor.
o
[2]
Anesia performs two experiments in a Form Five physics laboratory.
The diagram below shows the first experiment. She wraps two coils (A and B) around
an iron ring. A DC supply and a switch S are connected to coil A. Coil B is connected
to a sensitive centre-zero galvanometer.
a) State the observation in EACH scenario below:
i)
the switch S is closed.
[2]
ii) the switch S is kept closed.
[1]
91
Electromagnetism «(ont.)
iii) the switch S is opened.
[2]
b) In the second experiment, a stiff straight conductor is positioned between two
magnets. A sensitive centre-zero galvanometer is connected across the ends of the
conductor.
Stiff straight conductor
5
State the observation in EACH scenario below:
i)
the conductor is moved left and right horizontally.
[1]
ii) the conductor is moved up and down.
[21
iii) the conductor is moved up and down at a faster rate than in ii).
[2]
92
o
The diagram below shows a simple DC motor:
a) Identify the components A and B.
A ______________________________________________________
B __________________________________________________
[21
b) State the function of component A.
[11
c) Draw an arrow on the diagram to indicate the direction of the current flowing
through the coil.
[11
d) Explain the operation of the DC motor and state the direction of rotation of the coil.
[61
93
Electromagnetism (cont.)
e) State TWO changes that can be made to the DC motor to increase its speed of
rotation.
[2]
"
a) Sketch the magnetic field produced by a solenoid.
[1]
b) An electromagnetic relay is a device used to turn on a secondary circuit carrying a
large current, which can be very dangerous. The diagram below shows one type of
electromagnetic relay:
A
c
E
D
94
Identify the components A, B, C, D and E.
A ______________________________________________
B__________________________________________________
C ________________________________________________
D _________________________________________________
E __________________________________________________
[5)
c) Describe the operation of this electromagnetic relay.
[5)
G An electromagnet can be made by using a coil of copper wire and d.c. power supply.
a) State one advantage of an electromagnet over a permanent magnet.
[1)
b) State one use of an electromagnet.
[1)
c) State two ways of increasing the strength of an electromagnet.
[2)
<
95
Total Marks _
/74
Models of the atom
o
a) Briefly describe the
J J Thompson model of the atom.
(3)
b) Briefly describe the Rutherford model of the atom.
(3)
c) Describe the Geiger-Marsden experiment. State the results of this experiment and
outline what the results suggested about the structure of atoms.
(8)
<
96
Total Marks .
. . 114
Structure of the atom
o
a) Explain what is meant by EACH of the following terms:
i)
atomic number.
[1]
ii) mass number.
[1]
iii) neutron number.
[1]
b) Complete the following table:
Particle
Electron
Proton
Neutron
Location
Relative Mass
inside the nucleus
Relative Charge
+1
1
[6]
c) Describe the relationship between the shell model of the atom and the periodic table.
[1]
97
Structu re of the atom (cont.)
d) Carbon-14 is an isotope of carbon. The mass number is 14 and the atomic number is 6.
i)
State the number of electrons, protons and neutrons present in an atom of
carbon-14.
electrons _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
[1]
protons _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ____
[1]
neutrons _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
[1]
ii) Draw a diagram showing the structure of the carbon-14 atom.
[5]
98
e) Sodium-23 and sodium-24 are isotopes. The atomic number of sodium is 11.
i)
Explain what is meant by the term 'isotope'.
(2)
ii) Complete the following table:
Sodium-23
Sodium-24
Number of electrons
Number of rotons
Number of neutrons
(6)
iii) Suggest another isotope of sodium in the form
~ x.
[1 )
<
99
ar_k_s _____1_2_7--l
Total M_
E3
o
~
Radioactivity
a) Complete the following table:
Nature of the radiation
Char e
Sto
[9)
b) Compare the tracks produced by alpha particles and beta particles in a cloud chamber.
[5)
c) A radioactive source emits all three types of radiation in a). Complete and label the
path taken by EACH type of radiation in a magnetic field and an electric field.
i)
magnetic field
[3)
MagnetIC field
into the page
Radioactive
source
ii) electric field
[3]
+
+
Radioactive
source
100
+
+
+
d) Briefly describe an experiment to measure the range of alpha and beta particles.
o
[4]
Iodine-131 is a radioisotope with a half-life of 8 days.
a) Explain what is meant by the following terms:
i)
a radioisotope.
[2]
ii) half-life.
[2]
b) State THREE uses of radioisotopes.
[3]
c) A sample of iodine-131 has an initial activity of 8000 Bq.
i)
Calculate the activity of the sample after 24 days.
[3]
101
Radioactivity (cont.)
ii) Determine the elapsed time when the activity is reduced to 500 Bq.
[3)
iii) A sample of iodine-13l has an activity of 5000 Bq. A Form Four student suggested
that the activity of the sample can be increased by heating it strongly. State
whether this statement is correct, and provide an explanation for your answer.
o
[2)
a) Albert Einstein's famous equation E = me' is used to determine the amount of energy
released in nuclear reactions. State what EACH of the symbols in the equation means.
E __________________________________________________
m _______________________________________________________________
c ____________________________________________________________
[3)
b) The Caribbean is heavily dependent on oil and gas to meet its energy demands.
One island is deciding whether to build a nuclear power plant to meet its energy
needs. Briefly discuss TWO arguments FOR, and TWO arguments AGAINST,
such a decision.
For
[4)
102
Against
[4)
c) The following nuclear equation represents a fission reaction. The uranium-235
nuclide absorbs a neutron and splits into krypton-90, barium-144 and two neutrons
with the release of energy.
Use the data provided to calculate the energy released in this reaction.
Nuclide
uranium-235
krypton-90
barium-144
neutron
c = 3·0
X
Atomic mass/u
235·0439
89·9195
143·9230
1·0087
10 8 ms-I, u
= 1·66 X 10-27 kg
[7)
103
Radioactivity (cont.)
•
Yashoda has two radioactive samples, A and B. She measures the count rate (S-I) of
both samples over a period of 60 minutes. She plots the variation of count rate with
time for sample A and sample B:
Count
rate!s-l
50
Sample A
•
•
i-
1-
40
.
-+-
30
20
10
0
-j
I
I
I
•
1
10
20
30
40
50
60
tlmin
a) State THREE precautions that should be taken when handling radioactive samples.
[3]
b) Use the graph to determine the average half-life of sample B.
[3]
c) The graph for sample B does not pass through all the points. State what this
indicates about the nature of radioactive decay.
[1]
104
d) Comment on the half-life of sample A.
[1]
e) Another sample of B - same amount as in parts b) and c) - is heated strongly and
the count rate is measured over a period of 60 minutes. What effect will this have on
the shape of the graph, if any? Explain your answer.
o
[2]
a) A nucleus of uranium-238 (':~U)
decays to form a nucleus ofthorium (Th) by the
emission of an alpha particle. Write a nuclear equation for this reaction.
[2]
b) Radium-228 is a radioactive isotope. Its atomic number is 88 and it decays as follows:
• Radium-228 decays by emitting one alpha particle to form an isotope of radon (Rn).
• Radon decays by emitting one alpha particle to form an isotope of polonium (Po).
• Polonium decays by emitting two alpha particles to form an isotope oflead (Pb).
• The lead isotope emits a beta particle to form an isotope of bismuth (Bi).
Write ONE nuclear equation for EACH of the FOUR steps above.
[4]
<
105
Total Marks
___ _ __ /73
Collins
CSEC® PHYSICS WORKBOOK
This CSEC® Physics Workbook is an invaluable activity book for CSEC ® Physics students.
It covers all aspects of the Caribbean Examinations Council 's Certificate of Secondary
Education Physics syllabus. It provides excellent practice for the structured questions from
Paper 2 of the CSEC ® Examination and is a great aid to revision and examination practice.
The book features:
• Questions and activities on all aspects of the Physics syllabus
• Clear diagrams, charts and graphs for data analysis activities
• Clear mark allocations to indicate the value of each question part
Answers are available online at www.collins .co.uk/caribbeanschools
About the author
Terry David, the author, has written several texts on Physics. He is a former teacher
at St Joseph 's College, St Joseph, Trinidad and Tobago . He has prepared students for
the CXC examinations privately for over 10 years and provides tutoring videos online.
CSEC · workbook range
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