form 5 physics time: 2 hours - dlap...
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Physics – Secondary Schools - Track 3 – Form 5 – 2016 Page 1 of 16
DIRECTORATE FOR QUALITY AND STANDARDS IN EDUCATION
Department of Curriculum Management
Educational Assessment Unit
Annual Examinations for Secondary Schools 2016
FORM 5 PHYSICS TIME: 2 hours
Name: _____________________________________ Class: _______________
Answer ALL questions in the spaces provided on the Examination Paper.
All working must be shown. The use of a calculator is allowed.
Where necessary take the acceleration due to gravity 𝐠 = 𝟏𝟎 𝐦/𝐬𝟐.
Marks Grid: For the Examiners’ use ONLY
Question 1 2 3 4 5 6 7 8 9 10 11 12 Th. Prac Total Final Mark
Mark 10 10 10 10 10 10 10 20 20 20 20 20 170 30 200 100
Score
Density m = ρ V
Pressure P = ρ g h F = P A
Moments Moment = F × perpendicular distance
Energy PE = m g h KE =
1
2mv2 Work Done = F s
Work Done = Energy Converted E = P t
Force F = m a W = m g
Motion Average Speed =
total distance
total time s =
(u + v) t
2 s = ut +
1
2at2
v = u + at v2 = u2 + 2as Momentum = m v
Electricity
Q = I t V = I R E = Q V
P = I V R ∝ 𝐿/𝐴 E = I V t
RT = R1 + R2 + R3 1
RT=
1
R1+
1
R2
Electromagnetism N1
N2=
V1
V2
Heat ΔQ = m c Δθ
Waves
η =real depth
apparent depth η =
the speed of light in air
the speed of light in medium
v = f λ
f =1
T
m =hi
ho=
image distance
object distance
Radioactivity A = Z + N
Track 3
Page 2 of 16 Physics – Secondary Schools - Track 3 – Form 5 – 2016
Section A: This section has 7 questions. Each question carries 10 marks (70 marks).
1. An archer uses his bow as shown in Figure 1. He pulls and then releases
the string aiming his arrow towards a target.
a) Tick the correct statement. The archer is doing work
when holding the string in the position shown;
after releasing the string to fire the arrow;
as the string is pulled back to the position shown. [1]
b) What type of energy is present when the bow is bent?
_______________________________________________________________________________ [1]
c) The moving arrow has both ______________ energy and gravitational potential energy. [1]
d) The energy mentioned in (c) above changes into two other forms when the arrow hits the target.
Name these forms of energy.
_______________________________________________________________________________ [2]
e) His friend prefers to use a slingshot (hand catapult) instead,
as shown in Figure 2. He fired a small rock of mass 0.2 kg,
vertically upwards so that it rises to a maximum height of
5 m.
i) Underline: When the rock reaches its maximum height
it has (elastic potential energy, kinetic energy,
gravitational potential energy) [1]
ii) Calculate the energy of the rock when it reaches its maximum height.
_______________________________________________________________________________
____________________________________________________________________________ [2]
iii) The rock eventually falls down back to the ground. Calculate the velocity with which it hits the
ground.
_______________________________________________________________________________
_______________________________________________________________________________
____________________________________________________________________________ [2]
Figure 1
Figure 2
string bow
arrow
Physics – Secondary Schools - Track 3 – Form 5 – 2016 Page 3 of 16
2. Peter and his family went to a magic show. The diagram below shows an optical illusion used by
magicians. Peter said to his mother that it is sometimes called the ghost theatre illusion.
Figure 3
a) Add rays to show how the image of the actor behind the glass sheet is formed. [2]
b) Label clearly the angle of incidence i and the angle of reflection r. [2]
c) The image formed is called a virtual image. What is meant by a virtual image?
__________________________________________________________________________________
_______________________________________________________________________________ [2]
d) When they arrived home from the magic show Peter wanted to show another optical phenomenon
to his family. He shone a beam containing a mixture of red and blue light into a prism as shown in
Figure 4.
Figure 4
i) On the above diagram draw the path of the blue light as it passes through the prism and its
position on the screen. [3]
ii) Underline: This optical phenomenon is known as (diffraction, dispersion, focusing). [1]
Prism
Scre
en
Red + Blue
Light
Red Light
Page 4 of 16 Physics – Secondary Schools - Track 3 – Form 5 – 2016
3. Figure 5 shows the apparatus used to investigate the absorption of radiation from a radioactive source.
Figure 5
Different absorbing materials are placed between the source and the G-M tube. The table below shows
the count rate obtained with each of the four absorbers.
Absorbing material Counts/ s
Air 500
Sheet of paper 501
Thin sheet of aluminium 315
Thin sheet of lead 100
a) The source is not emitting alpha particles. How can you tell from the above table?
__________________________________________________________________________________
_______________________________________________________________________________ [2]
b) Is the source emitting beta particles? Explain.
__________________________________________________________________________________
_______________________________________________________________________________ [2]
c) What is the evidence that γ-rays are being emitted?
_______________________________________________________________________________ [2]
d) In a different experiment, a science student placed a radioactive source in front of the Geiger-
Muller tube and measured the count rate every 15 minutes.
Time /mins Count rate /mins Corrected count rate /mins
0 860 830
15 662 632
30 530 500
45 440 410
60 342 312
i) From the table, calculate the background radiation.
____________________________________________________________________________ [1]
Geiger Muller tube
Counter Source
Absorbing material
Physics – Secondary Schools - Track 3 – Form 5 – 2016 Page 5 of 16
ii) Define the term half-life.
____________________________________________________________________________ [1]
iii) Estimate the half-life of this radioactive source using the information given in the above table.
_______________________________________________________________________________
____________________________________________________________________________ [2]
4. Rose designed a device to compress crushed material for the school science fair.
The hinge acts as a pivot. A force of 50 N is applied downwards on the right-hand end of the lever
beam. Ignore the weight of the lever beam.
a) State ONE of the conditions necessary for a body to remain in equilibrium.
__________________________________________________________________________________
_______________________________________________________________________________ [1]
b) Calculate the moment of the 50 N force about the hinge.
__________________________________________________________________________________
_______________________________________________________________________________ [3]
c) Underline: The 50 N force exerts a (clockwise, anticlockwise) moment about the hinge. [1]
d) Using the law of moments, calculate the upward force F which the crushed material exerts on the
piston.
__________________________________________________________________________________
_______________________________________________________________________________ [2]
e) The cross-sectional area of the piston in contact with the crushed material is 0.003 m2. Calculate
the pressure exerted on the crushed material by the piston.
_______________________________________________________________________________ [2]
crushed material
piston lever beam hinge
50 N
55 cm 10 cm
F
Page 6 of 16 Physics – Secondary Schools - Track 3 – Form 5 – 2016
f) Underline. If the cross-sectional area of the piston is increased the pressure on the crushed material
will (increase, remain the same, decrease). [1]
5. The Universe is everything we can touch, feel, sense, measure or detect. It includes living things,
planets, stars, galaxies, dust clouds, light, and even time. The table below lists some facts about the
Universe that maybe True or False.
a) Mark with a [] whether the statement is True or False.
Statement True False
i. The Moon can be observed only during the night.
ii. The Sun is one of the millions of stars in our galaxy.
iii. A planet is stationary and emits light.
iv. There are 9 major planets in our solar system.
v. The Earth spins on its axis once every 24 hours
[5]
b) The Earth experiences four seasons. State ONE factor that causes the seasons on Earth.
__________________________________________________________________________________
_______________________________________________________________________________ [2]
c) Astronomers have discovered a new Solar system. A diagram of this solar system is shown below.
Figure 6
Complete the following sentences by using words from the following list.
(universe, planet, orbit, star, milky way, gravitational, comet)
i) X is at the centre of the solar system. X is a ____________________________________ [1]
ii) A orbits around X. A is called a ______________________________________________ [1]
iii) The ______________________force keeps A, B,C, D and E orbiting around X. [1]
X
Physics – Secondary Schools - Track 3 – Form 5 – 2016 Page 7 of 16
6. The diagram below shows a head-on collision between a car of mass 900 kg and a truck of mass
2000 kg.
Figure 7
a) Calculate the momentum of the car before collision.
_______________________________________________________________________________ [2]
b) Calculate the momentum of the truck before collision.
_______________________________________________________________________________ [1]
c) Taking into consideration that it is a head-on collision, calculate the total momentum before
collision.
_______________________________________________________________________________ [2]
d) What is the value of the total momentum after collision?
_______________________________________________________________________________ [1]
e) On another occasion, a driver accidentally leaves a packet resting on
the roof of his car as shown in the diagram.
i) What happens to the package when the driver brakes suddenly?
_______________________________________________________
_____________________________________________________[1]
ii) Which of Newton’s Laws explains your answer in (i) above? State
this law.
_______________________________________________________________________________
____________________________________________________________________________ [3]
7. A small private plane takes two minutes to travel between two
Greek islands.
a) Mark on the above diagram:
i) the weight of the plane; [1]
ii) the air resistance. [1]
20 m/s 15 m/s
Figure 8
Page 8 of 16 Physics – Secondary Schools - Track 3 – Form 5 – 2016
b) The graph below shows the journey of the plane between the two islands.
Figure 10
Use the graph to answer the following questions.
i) Calculate the acceleration of the plane as it takes off.
_______________________________________________________________________________
____________________________________________________________________________ [2]
ii) Mark on the graph the section where the plane flies at constant speed. Label as AB. [1]
iii) How much time does it take the plane to decelerate and land on the other island?
____________________________________________________________________________ [1]
iv) Calculate the total distance travelled by the plane.
_______________________________________________________________________________
_______________________________________________________________________________
____________________________________________________________________________ [2]
v) Each airport has a runway that is about 500 m long. Explain why these airports cannot cater for
aeroplanes with a larger mass.
_______________________________________________________________________________
____________________________________________________________________________ [2]
Figure 9
Physics – Secondary Schools - Track 3 – Form 5 – 2016 Page 9 of 16
Section B. This section has 5 questions. Each question carries 20 marks (100 marks).
8. This question is about electromagnetism.
In 1831, Sir Michael Faraday began a great series of
experiments in which he discovered electromagnetic
induction. The principle discovered back then forms the
basis of operation of a modern magnetic rechargeable
torch.
When the torch is shaken, the magnet moves through the coil and back again. This movement induces
a voltage across the ends of the coil. The voltage is used to provide current to recharge the battery in
the control unit.
i) Explain why a voltage is induced.
_______________________________________________________________________________
_______________________________________________________________________________
____________________________________________________________________________ [3]
ii) State TWO ways to increase the induced voltage.
_______________________________________________________________________________
____________________________________________________________________________ [2]
iii) The torch uses an LED. What does LED stand for? Draw its symbol in the space
provided.________________________________________________________ [2]
iv) Why is an LED ideal for such a setup?
_______________________________________________________________________________
____________________________________________________________________________ [2]
b) Electromagnetic induction
also occurs in a transformer.
Figure 14 shows a typical
transformer.
Figure 11
Figure 14
Figure 13 Figure 12
Page 10 of 16 Physics – Secondary Schools - Track 3 – Form 5 – 2016
i) Briefly explain how the transformer works.
_______________________________________________________________________________
_______________________________________________________________________________
____________________________________________________________________________ [3]
ii) Why is the core made of soft iron?
____________________________________________________________________________ [2]
iii) What type of transformer is shown in the above diagram?
____________________________________________________________________________ [1]
iv) If the primary coil has 8000 turns, calculate the number of turns in the secondary coil.
_______________________________________________________________________________
_______________________________________________________________________________
____________________________________________________________________________ [3]
v) State what would happen to the brightness of the lamp if the number of turns in the secondary
coil was much less than that calculated in (iv) above.
_______________________________________________________________________________
____________________________________________________________________________ [2]
9. This question is an experimental design about evaporation.
Isaac likes to use aftershave after shaving.
a) Explain in terms of molecules why the skin feels cool after applying aftershave.
__________________________________________________________________________________
__________________________________________________________________________________
_______________________________________________________________________________ [2]
b) Isaac accidentally left his aftershave plastic bottle on a windowsill where there is direct sunlight.
After a few hours Isaac observes that the plastic bottle expanded as shown in Figures 15 and 16.
Figure 15 Figure 16
Physics – Secondary Schools - Track 3 – Form 5 – 2016 Page 11 of 16
i) While in direct sunlight the _______________ energy of the molecules increases and this results
in a _____________ number of collisions with the wall of the container. The space between the
molecules will also ________________. [3]
ii) How would the pressure be different when compared to the above if the bottle were made of
glass? Explain.
_______________________________________________________________________________
_______________________________________________________________________________
____________________________________________________________________________ [3]
c) A scientist who works in a perfume manufacturing company produces two kinds of aftershaves.
She would like to test which aftershave evaporates the quicker before choosing which one to put on
the market.
i) The scientist has the following apparatus at hand: cotton wool, clamp and stand, two
thermometers, samples of each aftershave (aftershave X and aftershave Y) and a stopwatch.
Describe what she has to do to determine which aftershave has the largest cooling effect.
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
____________________________________________________________________________ [5]
ii) Mention ONE precaution that she should take to make sure the experiment is a fair experiment.
_______________________________________________________________________________
____________________________________________________________________________ [2]
iii) Which TWO variables should she plot on the graph?
_______________________________________________________________________________
____________________________________________________________________________ [2]
iv) Which of the two aftershaves could be smelt after a long period of time, the one which
evaporates the fastest or the one which evaporates the slowest? Give a reason for your answer.
_______________________________________________________________________________
____________________________________________________________________________ [3]
Page 12 of 16 Physics – Secondary Schools - Track 3 – Form 5 – 2016
10. This question is about waves
a) Mattias and Carl use a rope to propagate a wave as shown in Figure 17.
Figure 17
Determine:
i) the amplitude of the wave. _________ [2]
ii) the wavelength of the wave. ________ [2]
iii) the frequency of the wave, if it travels at 3 m/s.
_______________________________________________________________________________
____________________________________________________________________________ [3]
b) Some cars have parking sensors fitted to them. Ultrasound is used in these sensors.
Figure 18
i) Explain in your own words how the parking sensor uses ultrasound to work.
_______________________________________________________________________________
____________________________________________________________________________ [3]
ii) If the distance between the car and the wall is 170 cm, and the ultrasound is detected by the
sensor 0.01 s later, calculate the velocity of the ultrasound wave.
_______________________________________________________________________________
____________________________________________________________________________ [4]
dis
pla
cem
ent
/ cm
distance / cm
Physics – Secondary Schools - Track 3 – Form 5 – 2016 Page 13 of 16
iii) State what happens to the time taken for a transmitted wave to return back to the car if the car
moves closer to the wall.
_______________________________________________________________________________
____________________________________________________________________________ [2]
iv) A typical ultrasound wave used in the car parking sensor has a frequency of 40 000 Hz. Apart
from the ultrasound emitting device, why is a buzzer sound also fixed to the parking sensor?
_______________________________________________________________________________
____________________________________________________________________________ [2]
v) Give ONE other use for ultrasound waves apart from parking sensors.
____________________________________________________________________________ [2]
11. This question is about electrical circuits.
A 9 V battery is connected as shown in the circuit of Figure 19.
Figure 19
a) Find the total resistance between:
i) points Y and Z.
_______________________________________________________________________________
____________________________________________________________________________ [3]
ii) points X and Z
_______________________________________________________________________________
____________________________________________________________________________ [2]
b) Calculate the voltage across the rheostat.
__________________________________________________________________________________
_______________________________________________________________________________ [3]
4
13
12 X Y Z
9 V
Page 14 of 16 Physics – Secondary Schools - Track 3 – Form 5 – 2016
c) Find the value of the resistance of the rheostat so that a current of 0.5 A flows through the circuit.
Assume that the fuse has negligible resistance.
_______________________________________________________________________________ [2]
d) What is the function of the fuse in a circuit?
__________________________________________________________________________________
_______________________________________________________________________________ [2]
e) Calculate the maximum current that can flow through the circuit. Explain how this can be achieved
without changing the circuit.
__________________________________________________________________________________
_______________________________________________________________________________ [2]
f) Three fuses are available: 0.2 A, 0.6 A and 1.0 A. Which of these three fuses is the most suitable to
allow the maximum current calculated in part (e) to flow through it?_____________________ [1]
g) On the circuit of Figure 19, draw a voltmeter to measure the voltage across the rheostat. [2]
h) Should the resistance of the voltmeter be high or low? Explain.
__________________________________________________________________________________
_______________________________________________________________________________ [3]
12. This question is about density and thermal
energy.
Two students, Jasmine and Jake were given an
unknown solid of mass 340 g. They had to
determine the material that the solid was made
of. Jasmine and Jake decided to find the density
of the solid first.
a) Use the diagram to determine the volume of
the unknown solid.
______________________________________
______________________________________
___________________________________ [2]
Figure 20
Physics – Secondary Schools - Track 3 – Form 5 – 2016 Page 15 of 16
b) Calculate the density of the unknown solid.
__________________________________________________________________________________
__________________________________________________________________________________
_______________________________________________________________________________ [2]
c) Use the table below to determine the material the solid is made up of. Explain how you arrived at
your answer.
Material Aluminium Lead Rhodium Silver
Density g/cm3 2.7 11.3 12.5 10.5
__________________________________________________________________________________
_______________________________________________________________________________ [2]
d) To find the specific heat capacity of the solid, Jake used a 950 g block of the same solid with two
holes drilled in it. A thermometer was placed in one hole and a 95 W heater was placed in the other.
He lagged the solid using wool. The heater was switched on and the temperature was recorded every
3 minutes. The results are shown in the table below:
i) Plot a graph of Temperature on the y-axis against Time on the x-axis. [5]
ii) Find the gradient of the graph in order to determine the temperature rise per minute.
_______________________________________________________________________________
____________________________________________________________________________ [2]
iii) Calculate the energy supplied by the 95 W heater to the solid in 12 minutes assuming there are
no heat losses.
____________________________________________________________________________ [2]
iv) Calculate the specific heat capacity of the unknown solid of mass 950 g.
_______________________________________________________________________________
____________________________________________________________________________ [3]
v) Explain why the solid was lagged using wool.
_______________________________________________________________________________
____________________________________________________________________________ [2]
Temperature/ oC 15 35 55 75 95
Time / minutes 0 3 6 9 12
Page 16 of 16 Physics – Secondary Schools - Track 3 – Form 5 – 2016