ST VENERA BOYS’ SECONDARY SCHOOL
HALF-YEARLY EXAMINATIONS 2014-15
Form 3
Physics (Track 2)
Time: 1hr 30mins
Name: _____________________________
Class: ___________
Answer ALL questions in Section A and Section B.
All working must be shown. The use of a calculator is allowed.
Where necessary, take the gravitational field strength on Earth as g = 10N/kg.
Useful Equations:
Density
ρ=
Weight
W=m×g
Moments
M = Force × perpendicular distance
Pressure
P=
For examiner’s use:
1
2
3
(10)
(10)
(16)
4
(4)
P=h×ρ×g
5
(15)
6
(15)
Page 1 of 11
7
(15)
Main
(85)
Practical Total
(15)
(100)
SECTION A
Answer all questions in this section. This section carries 40 marks.
1. Complete the following sentences by writing the name of the instrument used and
the S.I unit.
(1 mark each – 10 marks)
a.
i) The ____________________ is used to measure the length of the
table.
ii) The standard units are ____________.
b.
i) The ____________________ is used to measure the time to run
across the yard.
ii) The standard units are ____________.
c.
i) The ____________________ is used to measure the mass of an
empty beaker.
ii) The standard units are ____________.
d.
i) The ____________________ is used to measure the volume of
some oil.
ii) The standard units are ____________________.
e.
i) The ____________________ is used to measure the weight of a
body.
ii) The standard units are ____________________.
Page 2 of 11
2. The diagram below shows the forces acting on an aeroplane flying at a constant
height.
i.
What are the forces labelled G and H?
_______________________________________________________________________________
_____________________________________________________________________ (2 marks)
ii. Force G is equal to 40000 N. The horizontal resultant force is zero. What is the size
of the thrust force?
__________________________________________
(1 mark)
iii. The aeroplane now needs to accelerate forward. What can be said about the
sizes of the thrust force and force G? (Underline the correct answer.)

The thrust force is greater than force G.

The thrust force is equal to force G.

The thrust force is smaller than force G.
(1 mark)
iv. The aeroplane has a mass of 80000 kg. What is its weight in Newtons?
_______________________________________________________________________________
_______________________________________________________________________________
_____________________________________________________________________(2 marks)
Page 3 of 11
v. The aeroplane is travelling at constant height. What can be said about the size of
the lift force and force H? (Underline the correct answer.)

The lift force is greater than force H.

The lift force is equal to force H.

The lift force is smaller than force H.
(1 mark)
vi. Suggest a suitable value for the lift force if the aeroplane needs to go higher.
__________________________________________
(1 mark)
vii. Is force a scalar or a vector quantity? Explain.
_____________________________________________________________________ (2 marks)
3. Ms Caruana works in a school. She received a new chair for her class.
The chair has a mass of 36kg.
a. What is the weight of the chair?
______________________________________________________________________________________
____________________________________________________________________________(2 marks)
b. The chair rests on four legs. Each leg has an area of 0.01m by 0.01m. Calculate
the total are in contact with the floor.
_______________________________________________________________________________
_____________________________________________________________________(3 marks)
c. Calculate the pressure the chair exerts on the floor.
_______________________________________________________________________________
_____________________________________________________________________(2 marks)
d. To decorate her classroom, Ms Caruana buys a new aquarium. Given that the
water in the aquarium is 0.5m high and the density of water is 1000kg/m3, what is
the pressure at the bottom of the aquarium?
_______________________________________________________________________________
_____________________________________________________________________(3 marks)
Page 4 of 11
e. A hydraulic press was given to the school where Ms Caruana works, so that waste
paper could be compressed into bundles.
Compressed
waste paper
bundles
30N
Area =
Area = 0.36m2
0.0007m2
Piston B
Piston A
i.
If a force of 30N is applied to Piston A, calculate the pressure in the oil at A.
_________________________________________________________________________
________________________________________________________________(2 marks)
ii.
What is the pressure exerted by the oil at B.
_____________________________
iii.
(1 mark)
Calculate the upward force acting on the large Piston.
_________________________________________________________________________
________________________________________________________________(3 marks)
4. Look at the sentences below. Fill in the missing words.
a. A body behaves as if its whole weight were concentrated at one point. This point
is called the ________________________.
(1 mark)
b. A sports car tends to have a ___________ centre of gravity. As a result, they are
more ____________.
(2 marks)
c. The centre of gravity of a cruise ship shifts ____________ as passengers move from
the lower to the upper decks.
(1 mark)
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SECTION B
Answer all questions in this section. This section carries 45 marks.
5. This question is about the extension of a spiral spring.
The table shows the results obtained when different stretching forces (F) are applied
to a spiral spring causing it to stretch.
Stretching Force (N)
0
2
Extension (mm)
0
4
4
6
8
9
12
16
20
a. Complete the missing data in the table.
(1 mark)
b. Plot a graph of the stretching force (x-axis) against the extension (y-axis) on the
graph paper provided.
(7 marks)
c. From the graph:
i.
A stretching force of _________ N produces an extension of 6mm.
(1 mark)
ii.
A force of 5N produces an extension of _________mm.
(1 mark)
iii.
The greatest load which can be loaded on this spring without damaging it
is _________N. This is referred to as the ______________ limit of the spring.
Mark this point with a letter E on your graph.
(3 marks)
d. From the graph it can be concluded that the stretching force is _______________
_______________ to the extension, since the graph is a _______________
_____________ through the origin.
(2 marks)
Page 6 of 11
Page 7 of 11
6. This question is about moment.
a. The figure below shows a heavy rock weighing 800 N. A man tries to lift the rock
by means of a solid iron lever, 2 metres long. The lever is pivoted at 40 cm from
the centre of the rock.
i.
Mark on the diagram the weight of the rock by means of an arrow and
label it 800N.
(1 mark)
ii.
Convert 2m to cm.
__________________________________
iii.
Find the distance marked ‘x’ on the diagram.
(1 mark)
(2 marks)
_________________________________________________________________________
iv.
Calculate the clockwise moment about the pivot.
(2 marks)
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
v.
Use the principle of moments to calculate how much force must the man
use in order to just lift the rock.
(2 marks)
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
Page 8 of 11
b. The diagram below shows a uniform ruler balanced on a fulcrum with a weight of
1.5N hanging from one end.
i.
What name is given to the point A?
(1 mark)
_________________________________________________________________________
ii.
Add to the diagram an arrow to show the weight of the ruler. Label it W.
(1 mark)
iii.
Calculate the anticlockwise moment about the fulcrum.
(2 marks)
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
iv.
By using the principle of moments about the fulcrum, calculate the weight
of the ruler.
(3 marks)
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
Page 9 of 11
7. This question is about density.
a. Solve the same problem as Archimedes using the information given here.
A
B
C
Mass in grams
3800
3800
3800
Volume in cm2
380
200
300
The density of gold is 19g/cm3
The density of silver is 10g/cm3
i.
Work out the density of trophy A.
(1 mark)
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
ii.
Work out the density of trophy B.
(1 mark)
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
iii.
Work out the density of trophy C.
(1 mark)
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
iv.
Decide which trophy is gold, which is silver and which is a mixture and give
an explanation for your answer.
(1 mark)
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
Page 10 of 11
b. Daniel wanted to find the density of lemonade. Fill in the missing words to explain
how he can find the volume, mass and density of the lemonade.

To find the volume of lemonade, pour the lemonade into the ________________
_______________ and read its volume at _______________ _______________ with
the meniscus.

(2 marks)
To find the mass of the lemonade we have to use a ______________.
First
measure the mass of the ________________ beaker and then fill it in with the
volume of lemonade. Now measure the new mass of the beaker filled with
_______________. Finally _______________ the readings of the masses taken to

find the mass of the volume of lemonade alone.
(4 marks)
To find the density of the lemonade simply use the equation
(1 mark)
____________________________________________________________________________
c. Daniel observed the upward flow of the gas bubbles in the lemonade. Explain this
flow.
(2 marks)
_______________________________________________________________________________
_______________________________________________________________________________
d. Daniel fills a measuring cylinder with 55cm 3 of lemonade. When he puts
some ice flakes in the lemonade, the total level rises to 85cm3.
Determine the volume of the ice inside the cylinder.
(2 marks)
______________________________________________________________________
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