SPM paper 2. All essay questions in chapter 3: Force and Pressure

1. Soalan esei spm kertas 2

2. SPM
2005

9. Aerofoil //
aerodynamic
SPM
2007

10. Higher velocity on the upper surface
Lower pressure on the upper
surface
Lift force = Difference in pressure x
Area of surface
// difference in pressure produce lift
force

12. In diagram 9.2 : less bending
In diagram 9.3: more bending

13. In diagram 9.3 : further // longer landing
distance
In diagram 9.2: shorter (landing distance)

14. The higher the lift force, the further
the landing distance
lift force is directly proportional to
landing distance

15. • Long jump // triple jump // glider
• Relationship between the lift force and
the landing distance is the higher the
lift force the further the landing
distance // directly proportional

18. Modification Reason
1. Smooth //coat
with wax // slippery
2. Reduce friction
/resistance //reduce
drag
3. Stream line //
aerodynamic //
torpedo // sharp
end // bullet//
diagram
4. Reduce friction /
resistance / drag

19. 5. Low density
material // strong
material // carbon
composite // fiber
glass // tough
material // wood
6.Easy to float // not
easy to break //
slides faster //
increase the speed //
light // withstand
high force of wave.
7.Water proof //
strong // nylon //
tough // plastic //
synthetic fiber //
canvas // synthetic
polymer
8.to avoid the sail
absorbs water //
avoid sail become
heavier // sail lighter
// not easy to tear
off// //small load

20. 9.Wide // big // large
//not too big
10 trap more wind //
bigger force //
increase resistance
towards air //
withstand strong
wind

21. SPM
2009

24. Diagram 9.1 shows a boy and his father
sitting on two identical beach balls, A
and B, respectively.
SPM
2010
Their weights are balanced by the
buoyant force.

25. What is the meaning of weight?
[1 mark]
Force exerted on every object
due to gravity

26. (i) Using Diagram 9.1, compare the
weight of the boy and his father, the
volume of the water displaced and the
buoyant force acted on both of them.
[3 marks]
• The weight of the
father is higher
• The volume of water
displaced by ball B is
bigger.
•The buoyant force
acted on the father is
bigger

27. State the relationship between the
buoyant force and:
The volume of water displaced
As the volume of water displaced
increases, the buoyant force increases
The weight of water displaced
Buoyant force = weight of water
[2 marks]
displaced
Name the physics principle involved.
Archimedes principle [1 mark]

28. (c) Diagram 9.2 shows what happens when a
wooden block is held above the water surface
and then released into the
water.
When the wooden block is released, it falls into
the water and goes completely under the water
surface. Then it moves upwards and floats on
the water surface.
Using the concept of buoyant force, explain why
the wooden block moves upwards and then
floats on the water surface. [3 marks]

29. 1st : Buoyant increases when the
volume of the immersed wooden
block increases.
2nd : buoyant force is larger than the
weight when the wooden block is
moving upwards.
3rd : Buoyant force equals to weight
of the wooden block when it is
floating on the surface of water.

30. (d) The State Forestry Department is going
to organize a raft competition. As a team
leader, you are required to give some
suggestions to design a raft which can
accommodate 15 participants and be able
to move quickly in water.

31. Using your knowledge of motion,
forces and properties of materials,
state and explain the suggestions,
based on the following aspects:
The shape of the raft [2 marks]
The material used for the raft [2 marks]
The size of the raft [2 marks]
The design of the raft. [4 marks]

32. Modification Reason
Streamline shape Reduce water
resistance
Low density material Can float easily
Bigger size Can accommodate
more participants
A few layers of Displaced more
water / higher
buoyant force
Attach plastic bottle,
drum/ polisterene
To increases
buoyant force
Attach sail / paddle/
fan / motor
Increase speed

33. • Diagram 11.1 shows a hydraulic jack which is
used to lift up a car. The working principle of
the hydraulic jack is based on the Pascal's
principle.
11
SPM
2011

34. (a) (i) State the Pascal's principle. [1 mark]
11
Pressure transmitted same/uniformly/equally
(ii) Explain how the hydraulic jack can be used to
lift a car when force F1 is applied on the small
piston with cross-section area Al. In your
explanation, state the reason why force F2 is
greater than force F1. [4 marks]
M1 – force produce pressure / P=F/A
M2 – pressure equally/equal / P1=P2 /
M3 – pressure act on A2 / pressure produce force / F2
= PA2
M4 – A2 > A1 / A2 greater / ratio A2:A1 greater then 1
M2 and M3 – pressure transmitted equally on A2

35. • Diagram 11.2 shows a hydraulic brake system
in a car.
11

36. • You are required to investigate the
characteristics of a hydraulic brake system as
shown in Table 11.
11

37. 11
• Explain the suitability of each characteristic
of the hydraulic brake system. Determine the
most effective hydraulic brake to be used in a
car brake system. Give reasons for your
choice. [10 marks]

38. • M1 – incompressible
• M2 – fluid can transfer / flow / pressure transmitted /
obey Pascal Principle
• M3 – high boiling point
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• M4 – not change to vapour / not easy to
evaporate/boil / dry out / vaporize / volume remain
constant
• M5 – high spring constant
• M6 – can withstand force / return quickly
• M7 – 1:5 / low ratio
• M8 – larger force / stop faster / easy to stop / easy to
slow down
• M9 – L
• M10 – because it is incompressible, has high boiling
point, high spring constant and low ration (1:5)

39. 11
In a hydraulic brake system, the cross-section
area of the pistons in the master cylinder and
the front wheel are 2 cm2 and 6 cm2
respectively. A force of 50 N is applied to the
piston in the master cylinder.
Calculate
(i) the pressure transmitted throughout the
brake fluid. [2 marks]
(ii) the force exerted on the piston of the front
wheel. [3 marks]

40. 11

41. 9 Two identical simple
Diagram 9.1 shows
the positions P and
Q at different
altitude.
barometers are placed at
both positions. The height
of the mercury column in
the barometers are shown
in Diagram 9.2.
SPM
2012
The density of air at P is 1.2 kgm-3 and the density of air at Q
is 1.0 kgm-3

42. What is the meaning of density? [1 mark]
Mass per volume
Using Diagram 9.1 and Diagram 9.2, compare the
altitudes of P and Q, the density of surrounding air
and the height of mercury column in the simple
barometer at positions P and Q. [3 marks]
1. Altitude Q is higher
2. Density of air at Q is lower
3. Height of mercury column Q is lower
9

43. State the relationship between the altitude and
The density of the air
The atmospheric pressure
[2 marks]
The higher the altitude, the lower the density
of air
The higher the altitude, the lower the
atmospheric pressure
9

44. Diagram 9.3 shows a dropper in a bottle.
Using the knowledge of atmospheric pressure,
explain how the liquid in the bottle can be
sucked into the dropper tube.
1. Press the dropper
2. Air inside the dropper is forced
out
3. Pressure inside decrease / low
4. Release the dropper
5. Atmospheric pressure push the
liquid // difference in pressure
9

45. 9
Diagram 9.4 shows a vacuum cleaner.
You are required to give some suggestions to
design a vacuum cleaner which can clean the dust
faster and effectively. Using the knowledge on
atmospheric pressure, Bernoulli’s principle and
properties of materials, explain your suggestion
based on the following aspects:
Material used for the body of vacuum cleaner.
Material used for the hose
The size of the fan
The size of the floor nozzle
The diameter of wand
[10 marks]

46. Material Low density
Strong / plastic
Lighter
Not easily break
Material of the
hose
Flexible / elastic
Strong
Easy to adjust
Does not tear
Twist/ moveable
Size of fan Bigger fan More air can be
sucked / lower
pressure inside
Floor nozzle Wider floor
nozzle
More dust is
sucked
Diameter of the
wand
Small diameter Lower pressure /
high velocity
9

47. Diagram 11.1 shows the cross section of the wing of
an aeroplane.
Name the shape of the aeroplane’s wing.
Aerofoil
………………………………………………………..[1 mark]
11

48. Explain how the aeroplane can lift up from the track
when it moves at high speed during take off.
[4 marks]
11 SPM
2013
√1 Air faster (at) top
√2 Small pressure (at) upper
√3 difference in pressure // P2 – P1 / P1 – P2
√4 Lift / force (idea of upward force) // F = PA // F //
PA // label diagram
√5 Bernoulli’s principle
Max 4 marks

49. An aeroplane with mass of 3.6 x 105 kg and total surface area of
460 m2 is at a constant height. The resultant force acting on the
aeroplane at that moment is zero.
(i) Calculate the weight of the aeroplane. [1 mark]
3.6 x 106 N
(ii) Determine the lifting force acting on the aeroplane. [1 mark]
3.6 x 106 N
(iii) Based on the answer in 11(b)(ii), calculate the pressure
difference between the upper and lower surfaces of the wings of
the aeroplane. [3 marks]
√1 3.6 x 106 = P1A – P2A
√2 Pressure difference = (3.6 x 106/460) //
(3.528 x 106)/460
√3 7826.09 Pa
11

50. Diagram 11.2 shows four design of perfume
sprays, P, Q, R and S with different specifications.
You are required to determine the most suitable
design of a perfume spray to produce a fine spray.
Study the specifications of the four perfume
sprays based on the following aspects:
(i) Size of the squeeze bulb.
(ii) Elasticity of the squeeze bulb.
(iii) Shape of the mid tube
(iv) Size of the nozzle.
Explain the suitability of each aspect and then
determine the most suitable design of a perfume
spray. Give reason for your choice.
[10 marks]
11

51. 11

52. √1 Big
11
√2 contain more air, produce greater pressure
√3 Elastic
√4 Less compression force required // easy to return to
original shape
√5 narrower at the middle of the tube
√6 Air travel faster to create lower pressure
√7 Small size
√8 Liquid carried out from the nozzle in a tiny droplets
// large coverage // increase coverage / area
√9 Perfume spray R
√10 Big size of squeeze-bulb, elastic squeeze-bulb,
narrower shape of the tube at the middle and small size
of nozzle