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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 1: Introduction to Physics Page 1 of 52
CHAPTER 1: INTRODUCTION TO PHYSICS 1.1 PENDULUM Hypothesis: The
longer the length of a simple pendulum, the longer the period of
oscillation. Aim of the experiment: To investigate how the period
of a simple pendulum varies with its length. Variables:
Manipulated: The length of the pendulum, l Responding: The period
of the pendulum, T Constant: The mass of the pendulum bob,
gravitational acceleration Apparatus/Materials: Pendulum bob,
length of thread about 100 cm long, retort stand, stopwatch
Setup:
Procedure: 1. The thread is tied to the pendulum bob. The other
end of the thread is tied around the
arm of the retort stand so that it can swing freely. The length
of the pendulum, l is measured to 80 cm as per the diagram.
Retort stand
Pendulum
Length, l Thread
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 1: Introduction to Physics Page 2 of 52
2. With the thread taut and the bob at rest, the bob is lifted
at a small amplitude (of not more than 10). Ensure that the
pendulum swings in a single plane.
3. The time for ten complete oscillations of the pendulum is
measured using the stopwatch.
4. Step 3 is repeated, and the average of both readings are
calculated. 5. The period of oscillation, T is calculated using the
average reading divided by the
number of oscillations, i.e. 10. 6. T2 is calculated by squaring
the value of T. 7. Steps 1 to 6 are repeated using l = 70 cm, 60
cm, 50 cm, and 40 cm. 8. A graph T2 versus l is plotted. Recording
of data:
Time of oscillations, t (s) Period of oscillation, T Length of
pendulum, l
(cm) t1 t2 Average T = t/10 (s) T2 (s2)
80 70 60 50 40
Graph of T2 vs l
Discussion: The graph of T2 versus l shows a straight line
passing through the origin. This means that the period of
oscillation increases with the length of the pendulum, with T2
directly proportional to l. Conclusion: The longer the length of
the pendulum, the longer the period of oscillation. The hypothesis
is proven valid.
Length of pendulum, l
T2
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 3 of 52
CHAPTER 2: FORCES AND MOTION 2.1 INCLINED PLANES Hypothesis: The
larger the angle of incline, the higher the velocity just before
reaching the end of the runway Aim of the experiment: To study the
relationship between the velocity of motion and the angle of
inclination Variables: Manipulated: Angle of incline Responding:
Velocity just before reaching the end of the runway Constant:
Length of runway Apparatus/Materials: Trolley, protractor, wooden
blocks, cellophane tape, ticker-timer, ticker tape, power supply,
friction-compensated runway Setup:
Procedure: 1. The apparatus is set up as per the diagram, and
the inclined angle of the plane is
measured using a protractor. An initial angle of 5 is used. 2.
The ticker-timer is started up and at the same time the trolley is
released to slide down
the plane. 3. The final velocity when the trolley reaches the
end of the plane is calculated using the
distance of 10 ticks on the ticker tape. 4. The procedure is
repeated by changing the angle of incline to 10, 15, 20 and 25.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 4 of 52
Results: Angle of incline () Final velocity (m s-1)
5 10 15 20 25
Analysis: A graph of the velocity of the trolley against the
angle of incline is plotted as follows:
Conclusion: A higher angle of incline will have a higher
velocity at the end of the runway. Hypothesis accepted. Note: The
experiment can be modified by making the angle constant and varying
the height and length of the runway. Changes must be made
accordingly: hypothesis, variable list, procedure, table, analysis,
conclusion.
Angle of incline ()
Velocity (m s-1)
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 5 of 52
2.2 INERTIA Option 1: Using a saw blade Hypothesis: The larger
the mass, the larger the inertia Aim of the experiment: To study
the effect of mass on the inertia of an object Variables:
Manipulated: Mass, m Responding: Period of oscillation, T Constant:
Stiffness of blade, distance of the centre of the plasticine from
the clamp Apparatus/Materials: Jigsaw blade, G-clamp, stopwatch,
and plasticine spheres of mass 20 g, 40 g, 60 g, 80 g, and 100 g
Setup:
Procedure: 1. One end of the jigsaw blade is clamped to the leg
of a table with a G-clamp as per the
diagram drawn. 2. A 20 g plasticine ball is fixed at the free
end of the blade. 3. The free end of the blade is displaced
horizontally and released so that it oscillates.
The time for 10 complete oscillations is measured using a
stopwatch. This step is repeated. The average of 10 oscillations is
calculated. Then, the period of oscillation is determined.
4. Steps 2 and 3 are repeated using plasticine balls with masses
40 g, 60 g, 80 g, and 100 g.
5. A graph of T2 versus mass of load, m is drawn.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 6 of 52
Results: Time of oscillations, t (s) Period of oscillation, T
Mass of
load, m (g) t1 t2 Average T = t/10 (s) T2 (s2) 20 40 60 80
100 Graph of T2 versus m:
Discussion: The graph of T2 versus m shows a straight line
passing through the origin. This means that the period of
oscillation increases with the mass of the load; that is, an object
with a large mass has a large inertia. Conclusion: Objects with a
large mass have a large inertia. This is the reason why it is
difficult to set an object of large mass in motion or to stop it.
The hypothesis is valid. Option 2: Using an inertia balance
Hypothesis: The larger the mass, the bigger the inertia Aim of the
experiment: To study the effect of mass on the inertia of an object
Variables: Manipulated: Mass, m Responding: Period of oscillation,
T Constant: Stiffness of the inertia balance Apparatus/Materials:
Inertia balance, masses for the inertia balance, G-clamp,
stopwatch
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 7 of 52
Setup:
Procedure: 1. The inertia balance is set up by clamping it onto
one end of the table as shown in the
figure above. 2. One mass is placed into the inertia balance.
The inertia balance is displaced to one
side so that it oscillates in a horizontal plane. 3. The time
for 10 complete oscillations is measured using a stopwatch. This
step is
repeated. The average of 10 oscillations is calculated. Then,
the period of oscillation is determined.
4. Steps 2 and 3 are repeated using two and three masses on the
inertia balance. 5. A graph of T2 versus number of masses, n is
drawn. Results:
Time of oscillations, t (s) Period of oscillation, T Number of
masses, n t1 t2 Average T = t/10 (s) T2 (s2)
1 2 3
Graph of T2 versus m:
Discussion: The graph of T2 versus m shows a straight line
passing through the origin. This means that the period of
oscillation increases with the mass of the load; that is, an object
with a large mass has a large inertia. Conclusion: Objects with a
large mass have a large inertia. This is the reason why it is
difficult to set an object of large mass in motion or to stop it.
The hypothesis is valid.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 8 of 52
2.3 PRINCIPLE OF CONSERVATION OF MOMENTUM Experiment 1: Elastic
collisions Hypothesis: The total momentum before collision is equal
to the total momentum after collision, provided there are no
external forces acting on the system Aim of the experiment: To
demonstrate conservation of momentum for two trolleys colliding
with each other elastically Variables: Manipulated: Mass of
trolleys Responding: Final velocities of the trolleys / Momentum of
the trolleys Constant: Surface of ramp used Apparatus/Materials:
Friction-compensated runway, ticker-timer, A.C. power supply,
trolleys, wooden block, ticker tape, cellophane tape Setup:
Procedure: 1. The apparatus is set up as shown in the diagram.
2. The runway is adjusted so that it is friction-compensated. 3.
Two trolleys of equal mass are selected. A spring-loaded piston is
fixed to the front
end of trolley A. 4. Two pieces of ticker tape are attached to
trolleys A and B respectively with
cellophane tape. The ticker tapes are separately passed through
the same ticker-timer. 5. The ticker-timer is switched on and
trolley A is given a slight push so that it moves
down the runway at uniform velocity and collides with trolley B
which is stationary. 6. The ticker-timer is switched off when both
trolleys reach the end of the runway. 7. From the ticker tapes of
trolleys A and B, the final velocities are determined. 8. Momentum
is calculated using the formula p = mv. 9. The experiment is
repeated using different masses of trolleys.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 9 of 52
Recording of data: Before collision After collision mA mB
uA Initial total momentum, mAuA
vA vB Final total momentum, mAvA + mBvB
m m m 2m
2 m m 2 m 2 m Analysis: From the above table, it is found
that:
Total momentum before collision = Total momentum after collision
Conclusion: Hypothesis proven. Experiment 2: Inelastic collisions
Hypothesis: The total momentum before collision is equal to the
total momentum after collision, provided there are no external
forces acting on the system Aim of the experiment: To demonstrate
conservation of momentum for two trolleys colliding with each other
inelastically Variables: Manipulated: Mass of trolleys Responding:
Final velocities of the trolleys / Momentum of the trolleys
Constant: Surface of ramp used Apparatus/Materials:
Friction-compensated runway, ticker-timer, A.C. power supply,
trolleys, wooden block, ticker tape, cellophane tape, plasticine /
Velcro Setup:
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 10 of 52
Procedure: 1. The apparatus is set up as shown in the diagram.
2. The runway is adjusted so that it is friction-compensated. 3.
Two trolleys of equal mass are selected. Plasticine is fixed to the
front end of trolley
A. (Alternatively, use Velcro pads) 4. A ticker tape is attached
to trolley A with cellophane tape. The ticker tape is passed
through the ticker-timer. 5. The ticker-timer is switched on and
trolley A is given a slight push so that it moves
down the runway at uniform velocity and collides with trolley B
which is stationary. 6. The ticker-timer is switched off when both
trolleys reach the end of the runway. 7. The final velocity is
determined from the ticker tape. 8. Momentum is calculated using
the formula p = mv. 9. The experiment is repeated using different
masses of trolleys. Results:
Before collision After collision mA mB u Initial total
momentum,
mAuA v Final total momentum,
(mA + mB) v m m m 2m
2 m m 2 m 2 m Analysis: From the above table, it is found
that:
Total momentum before collision = Total momentum after collision
Conclusion: Hypothesis proven. Experiment 3: Explosion Hypothesis:
The total momentum before collision is equal to the total momentum
after collision, provided there are no external forces acting on
the system Aim of the experiment: To demonstrate conservation of
momentum for two trolleys moving away from each other from an
initial stationary position Variables: Manipulated: Mass of
trolleys Responding: Final velocities of the trolleys / Momentum of
the trolleys Constant: Surface used
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 11 of 52
Apparatus/Materials: Trolleys, wooden blocks, ticker tape,
cellophane tape Setup:
Before explosion After explosion Procedure: 1. The apparatus is
set up as shown in the diagram. 2. Two trolleys A and B of equal
mass are placed in contact with each other on an even
and smooth surface. Two wooden blocks are placed on the same row
at the end of each trolley respectively.
3. The vertical trigger on trolley B is given a light tap to
release the spring-loaded piston which then pushes the trolleys
apart. The trolleys collide with the wooden blocks.
4. The positions of the wooden blocks are adjusted so that both
the trolleys collide with them at the same time.
5. The distances, dA and dB are measured and recorded. 6. The
experiment is repeated with different masses of trolleys.
Results:
Before explosion
After explosion
Initial total momentum
Mass of trolley A, mA
Mass of trolley B, mB
Distance traveled by trolley A, dA
Distance traveled by trolley B, dB
Final total momentum,
mAdA + mB(-dB) 0 m m 0 m 2m 0 2 m m 0 2m 2m
Analysis: Because both trolleys hit the wooden blocks at the
same time, the velocity of the trolleys can be represented by the
distance traveled by the trolleys. From the above table, it is
found that:
Initial total momentum = 0 Final total momentum = 0
Total momentum before collision = Total momentum after collision
Conclusion: Hypothesis proven.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 12 of 52
2.4 FORCE, MASS AND ACCELERATION Experiment 1: Relationship
between acceleration and mass when force is constant Hypothesis:
When the force applied is constant, the acceleration of an object
decreases when its mass increases Aim of the experiment: To study
the effect of mass of an object on its acceleration if the applied
force is constant Variables: Manipulated: Mass, m Responding:
Acceleration, a Constant: Applied force, F Apparatus/Materials:
Ticker-timer, A.C. power supply, trolleys, elastic band, runway,
wooden block, ticker tape, cellophane tape Setup:
Procedure: 1. Apparatus is set up as shown in the diagram. 2. A
ticker-tape is attached to the trolley and passed through the
ticker-timer. 3. The ticker-timer is switched on and the trolley is
pulled down the inclined runway
with an elastic band attached to the hind post of the trolley.
4. The elastic band must be stretched to a fix length that is
maintained throughout the
motion down the runway. 5. When the trolley reaches the end of
the runway, the ticker-timer is switched off and
the ticker tape is removed. 6. Starting from a clearly printed
dot, the ticker tape is divided into strips with each strip
containing 10 ticks. 7. A ticker tape chart is constructed, and
from the chart, the acceleration of the trolley is
calculated. 8. The experiment is repeated using 2 and 3
trolleys. The elastic band must be stretched
to the same fixed length as in step 4.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 13 of 52
Results: Mass of trolley, m (kg)
m1 Acceleration, a (m s
-2)
1 trolley 2 trolleys 3 trolleys Analysis:
A graph of a against m1 is drawn.
From the graph, it shows that m
a 1 Conclusion: The acceleration of an object decreases when the
mass increases. Hypothesis proven. Experiment 2: Relationship
between acceleration and force when mass is constant Hypothesis:
When the mass is constant, the acceleration of an object increases
when the applied force increases Aim of the experiment: To study
the effect of force on an objects acceleration if its mass is
constant Variables: Manipulated: Applied force, F Responding:
Acceleration, a Constant: Mass, m Apparatus/Materials:
Ticker-timer, A.C. power supply, trolleys, elastic band, runway,
wooden block, ticker tape, cellophane tape
m1
a
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 14 of 52
Setup:
Procedure: 1. Apparatus is set up as shown in the diagram. 2. A
ticker-tape is attached to the trolley and passed through the
ticker-timer. 3. The ticker-timer is switched on and the trolley is
pulled down the inclined runway
with an elastic band attached to the hind post of the trolley.
4. The elastic band must be stretched to a fix length that is
maintained throughout the
motion down the runway. 5. When the trolley reaches the end of
the runway, the ticker-timer is switched off and
the ticker tape is removed. 6. Starting from a clearly printed
dot, the ticker tape is divided into strips with each strip
containing 10 ticks. 7. A ticker tape chart is constructed, and
from the chart, the acceleration of the trolley is
calculated. 8. The experiment is repeated using 2 and 3 elastic
bands. The elastic bands must be
stretched to the same fixed length as in step 4. Results:
Force applied, F Acceleration, a (m s-2) 1 unit 2 units 3
units
Analysis: A graph of a against F is drawn.
From the graph, it shows that a F Conclusion: The acceleration
of an object increases when the applied force increases. Hypothesis
proven.
F
a
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 15 of 52
2.5 GRAVITATIONAL ACCELERATION Hypothesis: Gravitational
acceleration does not depend on an objects mass Aim of the
experiment: To measure the acceleration due to gravity Variables:
Manipulated: Mass, m Responding: Gravitational acceleration, g
Apparatus/Materials: Ticker-timer, ticker tape, A.C. power supply,
retort stand, weights (50 g 250 g), G-clamp, cellophane tape, soft
board Setup:
Procedure: 1. Apparatus is setup as shown in the diagram above.
2. One end of the ticker tape is attached to a 50 g weight with
cellophane tape, and the
other end is passed through the ticker timer. 3. The
ticker-timer is switched on and the weight is released so that it
falls onto the soft
board. 4. The ticker-timer is switched off when the weight lands
on the soft board. 5. Gravitational acceleration is calculated from
the middle portion of the ticker tape. 6. The experiment is
repeated with weights of mass 100 g, 150 g, 200 g, and 250 g.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 16 of 52
Results: Mass of weights (g) Free fall acceleration (m s-2)
50 100 150 200 250
Analysis: From the table above, it is found that the
gravitational acceleration for all the weights of different masses
are the same. Discussion: The value of the gravitational
acceleration, g obtained is less than the standard value
of 9.81 m s-2 This is because the weight is not falling freely.
It is affected by:
o Air resistance o Friction between ticker tape and
ticker-timer
Conclusion Gravitational acceleration is not dependent on the
mass of the object. Hypothesis proven. 2.6 PRINCIPLE OF
CONSERVATION OF ENERGY Hypothesis: Energy cannot be created or
destroyed, it can only change form. Aim of the experiment: To
investigate the conversion of gravitational potential energy to
kinetic energy. Variables: Manipulated: Mass, m Responding: Final
velocity, v Constant: Height, h Apparatus/Materials: Ticker-timer,
ticker tape, A.C. power supply, trolley, thread, weights, smooth
pulley, friction-compensated runway, soft board, cellophane
tape
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 17 of 52
Setup:
Procedure: 1. Apparatus is setup as shown in the diagram above.
2. One end of the ticker tape is attached to the back of the
trolley with cellophane tape
and the other end is passed through the ticker-timer. 3. The
ticker-timer is switched on, and the trolley is released. 4. The
final velocity of the trolley and the weight is determined from the
ticker tape
obtained. 5. The experiment is repeated with different masses of
trolleys and weights. Results: Mass of trolley = M kg Mass of
weight = m kg Height of weight before release = h m Final velocity
of trolley and weight = v m s-1 Loss of potential energy of the
weight = mgh Final kinetic energy of the trolley and the weight =
(M + m) v2 It is found that (M + m) v2 = mgh Conclusion The loss of
potential energy is converted to kinetic energy. Hypothesis proven.
Note: The experiment can be modified by making the mass constant
and changing the height of the weights release. Changes must be
made to the variables list and to the last step of the
procedure.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 18 of 52
2.7 HOOKES LAW Hypothesis: The bigger the weight, the longer the
spring extension Aim of the experiment: To determine the
relationship between the weight and the spring extension Variables:
Manipulated: Weight of the load Responding: Spring extension
Constant: Spring constant Apparatus and Materials: Spring, pin,
weights, plasticine, retort stand, metre rule Setup:
Procedure: 1. The apparatus is setup as shown in the diagram. 2.
The length of the spring without any weights, l0 is measured using
the metre rule with
the pin as reference. 3. A 50 g weight is hung from the bottom
of the spring. The new length of the spring, l
is measured. The spring extension is l l0. 4. Step 4 is repeated
with weights 100 g, 150 g, 200 g, and 250 g.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 2: Forces and Motion Page 19 of 52
Results: Original length of spring = l0 = __________ cm
Load mass (g)
Load weight (N)
Spring length, l (cm)
Spring extension, x = l l0 (cm)
50 g 0.5 N 100 g 1.0 N 150 g 1.5 N 200 g 2.0 N 250 g 2.5 N
Analysis: A graph of spring extension, x against weight, F is
plotted.
The x-F graph is a linear graph which passes through the origin.
This shows that the extension of the spring is directly
proportional to the stretching force. Conclusion: Hypothesis
proven.
F
x
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 3: Forces and Pressure Page 20 of 52
CHAPTER 3: FORCES AND PRESSURE 3.1 PRESSURE IN LIQUIDS
Experiment 1: Water pressure and depth Hypothesis: Water pressure
increases with depth Aim of the experiment: To find the
relationship between the pressure in a liquid according to its
depth Variables: Manipulated: Depth of liquid Responding: Pressure
in liquid Constant: Density of liquid Apparatus and Materials:
Measuring cylinder, thistle funnel, rubber tube, manometer, metre
rule Setup:
Procedure: 1. Apparatus is set up as shown in the diagram. 2.
The measuring cylinder is completely filled with water. 3. The
thistle funnel is lowered into the water to a depth of 10.0 cm. The
manometer
reading is measured. The difference in the liquid heights in the
manometer represent the pressure reading.
4. Step 3 is repeated with values of depth 20.0 cm, 30.0 cm,
40.0 cm and 50.0 cm.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 3: Forces and Pressure Page 21 of 52
Results: Depth (cm) Manometer reading (cm)
10.0 20.0 30.0 40.0 50.0
Analysis: A graph of pressure against depth is drawn.
Conclusion: It is observed that the manometer reading increases
as the depth of the thistle funnel increases. This shows that the
pressure increases with the depth of the liquid. Hypothesis proven.
Experiment 2: Water pressure and density Hypothesis: Pressure in
liquid increases with its density Aim of the experiment: To find
the relationship between the pressure in a liquid and its density
Variables: Manipulated: Density of liquid Responding: Pressure in
liquid Constant: Depth of liquid Apparatus and Materials: Measuring
cylinder, thistle funnel, rubber tube, manometer, metre rule,
water, glycerin, alcohol
Depth
Pressure
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 3: Forces and Pressure Page 22 of 52
Setup:
Procedure: 1. Apparatus is set up as shown in the diagram. 2.
The measuring cylinder is completely filled with water. 3. The
thistle funnel is lowered into the water to a depth of 50.0 cm. The
manometer
reading is measured. The difference in the liquid heights in the
manometer represent the pressure reading.
4. The experiment is repeated by replacing the water with
glycerin (density = 1300 kg m-3) and alcohol (density = 800 kg
m-3).
Results: Depth within liquid = 50.0 cm
Liquid Density (kg m-3) Manometer reading (cm) Water 1000
Glycerin 1300 Alcohol 800
Conclusion: It is observed that the manometer reading increases
as the density of the liquid increases. This shows that the
pressure increases with the density of the liquid. Hypothesis
proven.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 3: Forces and Pressure Page 23 of 52
3.2 ARCHIMEDES PRINCIPLE Hypothesis: The buoyant force on an
object in a liquid is equal to the weight of the liquid displaced
Aim of the experiment: To find the relationship between the buoyant
force acting upon an object in a liquid and the weight of the
liquid displaced Variables: Manipulated: Weight of the object
Responding: Buoyant force / Weight of liquid displaced Constant:
Density of liquid used Apparatus and Materials: Eureka tin, spring
balance, stone, thread, beaker, triple beam balance Setup:
Procedure: 1. A beaker is weighed with the triple beam balance
and its mass, m1 is recorded. 2. The Eureka tin is filled with
water right up to the level of the overflow hole. The
beaker is placed beneath the spout to catch any water that flows
out. 3. A stone is suspended from the spring balance with thread
and its weight in air, W1 is
read from the spring balance.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 3: Forces and Pressure Page 24 of 52
4. The stone is lowered into the Eureka tin until it is
completely immersed in water without touching the bottom of the
Eureka tin. The water will overflow into the beaker.
5. The spring balance reading, W2 is recorded. 6. The beaker
with water is weighed with the triple beam balance, and the mass,
m2 is
recorded. Results: Weight of stone in air = W1 Weight of stone
in water = W2 Buoyant force acting on the stone = W2 W1 Weight of
the empty beaker = m1g Weight of the beaker and displaced water =
m2g Weight of the displaced water = (m2 m1)g It is found that W2 W1
= (m2 m1)g Discussion: The loss of weight of the stone immersed in
water is due to the buoyant force of the water acting upon it. From
the results, it is found that the loss in weight of the stone is
equal to the weight of water displaced. Conclusion: Buoyant force
on the stone = Weight of the water displaced by the stone
Hypothesis proven. Note: Experiment can be modified to compare the
weight of different sized stones and the values of buoyant force
3.3 PASCALS PRINCIPLE Hypothesis: The liquid pressure exerted on a
small surface is equal to the liquid pressure exerted on a large
surface in a closed system Aim of the experiment: To find the
relationship between the pressure in a small syringe and a large
syringe in a closed system Variables: Manipulated: Pressure acting
on the small syringe Responding: Pressure acting on the large
syringe Constant: Density of liquid within the system
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 3: Forces and Pressure Page 25 of 52
Apparatus and Materials: 5 ml syringe, 10 ml syringe, several
weights, rubber tube, two retort stands Setup:
Procedure: 1. The diameters of the piston of both syringes are
measured and their cross-sectional
areas are calculated. 2. The two syringes are each mounted on a
retort stand. 3. The syringes are filled with water and are
securely connected to each other with a
rubber tube as shown in the diagram. 4. A weight is placed on
the piston of the small syringe. 5. Weights are added to the piston
of the large syringe until the water levels in the two
syringes are the same (i.e. syringes are in equilibrium). 6. The
forces, F1 and F2 on the syringes are calculated. 7. The pressure,
P1 and P2 exerted on the syringes are compared. Results:
Syringe
size Cross-sectional
area, A Mass of the weight, m
Force exerted on the syringe, F = mg
Pressure, P
= AF
Small A1 m1 F1 P1 Large A2 m2 F2 P2
Discussion: It is found that the pressure, P1 exerted on the
piston of the small syringe is equal to the pressure, P2 exerted on
the piston of the large syringe. Conclusion: The water pressure
exerted on the piston of the small syringe is equal to the water
pressure exerted on the piston of the large syringe. This shows
that the pressure applied to the piston of the small syringe is
transmitted to the piston of the large syringe. Hypothesis
proven.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 3: Forces and Pressure Page 26 of 52
3.4 BERNOULLIS PRINCIPLE Hypothesis: When the velocity of water
increases, its pressure decreases and vice versa. Aim of the
experiment: To find the effects of movement on the pressure exerted
by a fluid Variables: Manipulated: Velocity of the water
Responding: Pressure of the water Constant: Density of the water
Apparatus and Materials: Uniform glass tube, Venturi tube, rubber
hose, water from a tap Procedure: 1. A uniform glass tube is
connected to a tap with a rubber hose. The other end of the
tube is closed up with a stopper. 2. The tap is opened slowly so
that water flows into it. 3. The levels of the vertical tubes are
observed. 4. The stopper is then removed. The tap is adjusted so
that the water flows through the
tube at a uniform rate. 5. The levels of the vertical tubes are
observed. 6. The experiment is repeated by replacing the uniform
glass tube with a Venturi tube. Results: Uniform glass tube:
With the stopper Without the stopper
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 3: Forces and Pressure Page 27 of 52
Venturi tube:
With the stopper Without the stopper
Discussion: The height of the water in the vertical tube
represents the pressure at that point. When water is not flowing,
the pressure along the entire tube is the same, therefore
the water levels in all three vertical tubes are the same. For
the uniform glass tube:
o Water flows from high pressure to low pressure. o Therefore,
the water levels are decreasing because the pressure is
decreasing.
For the Venturi tube: o The velocity at Y is higher because of
the smaller cross-sectional area. o Therefore, the pressure at Y is
the lowest. o Pressure still decreases from X to Z because water
flows from high pressure to
low pressure. Conclusion: The higher the water velocity, the
lower the pressure at that point. Hypothesis proven.
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Chapter 4: Heat and Energy Page 28 of 52
CHAPTER 4: HEAT AND ENERGY 4.1 SPECIFIC HEAT CAPACITY Experiment
1: Rise in temperature varying mass, fixed amount of heat
Hypothesis: The bigger the mass of water, the smaller the rise in
temperature when supplied with the same amount of heat Aim of the
experiment: To determine the rise in temperature of water with
varying masses Variables: Manipulated: Mass of water, m Responding:
Rise in temperature, Constant: Amount of heat supplied, Q Apparatus
and Materials: Beaker, electric heater, thermometer, stopwatch,
triple beam balance, stirrer, polystyrene sheet, felt cloth Set
up:
Procedure: 1. With the help of a triple beam balance, fill a
beaker with water of mass 0.40 kg. 2. The apparatus is set up as
shown in the diagram. 3. The initial temperature of the water, 1 is
measured using a thermometer and is
recorded. 4. The electric heater is placed into the water and is
switched on for 1 minute. The water
is continuously stirred. 5. The water is continuously stirred
even after the heater has been switched off. The
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 29 of 52
6. The highest temperature the water reaches, 2 is measured and
recorded. The rise in temperature, = 2 1 is calculated.
7. The experiment is repeated with water of mass 0.50 kg, 0.60
kg, 0.70 kg, and 0.80 kg.
8. A graph of against m and a graph of against m1 are
plotted.
Results: Mass of water,
m (kg) Initial
temperature, 1 (C)
Final temperature,
2 (C)
Rise in temperature, = 2 1 (C)
m1 (kg-1)
0.40 0.50 0.60 0.70 0.80
Analysis: The amount of heat supplied is made constant by using
the same heater for the same
period of time. The following graphs are obtained:
Conclusion: The rise in temperature is inversely proportional to
the mass when a constant amount of heat is supplied. Hypothesis
proven. Experiment 2: Rise in temperature fixed mass, varying
amount of heat Hypothesis: When more heat is supplied to water of
fixed mass, the rise in temperature is greater Aim of the
experiment: To determine the rise in temperature of water with
varying amounts of heat Variables: Manipulated: Amount of heat
supplied, Q Responding: Rise in temperature, Constant: Mass of
water, m
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Chapter 4: Heat and Energy Page 30 of 52
Apparatus and Materials: Beaker, electric heater, thermometer,
stopwatch, triple beam balance, stirrer, polystyrene sheet, felt
cloth Set up:
Procedure: 1. With the help of a triple beam balance, fill a
beaker with water of mass 0.50 kg. 2. The apparatus is set up as
shown in the diagram. 3. The initial temperature of the water, 1 is
measured using a thermometer and is
recorded. 4. The electric heater is placed into the water and is
switched on for 1 minute. The water
is continuously stirred. 5. The water is continuously stirred
even after the heater has been switched off. 6. The highest
temperature the water reaches, 2 is measured and recorded. The rise
in
temperature, = 2 1 is calculated. 7. The experiment is repeated
with water of the same mass but with heating time of 2
minutes, 3 minutes, and 4 minutes. 8. A graph of against t is
plotted. Results:
Heating time (minute)
Initial temperature,
1 (C)
Final temperature,
2 (C)
Rise in temperature, = 2 1 (C)
1 2 3 4
Analysis: Because the same heater with fixed power is used, the
heating time, t is defined
operationally as the heat quantity. The following graph is
obtained:
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Chapter 4: Heat and Energy Page 31 of 52
Conclusion: When an object of fixed mass is heated, the rise in
temperature changes proportionally to the amount of heat supplied.
Hypothesis proven. Experiment 3: Determining the specific heat
capacity of aluminium Aim of the experiment: To determine the
specific heat capacity of aluminium Apparatus and Materials:
Aluminium cylinder, weighing scale, electric heater, thermometer,
power supply, felt cloth, polystyrene sheet, stopwatch, lubricating
oil Set up:
Procedure: 1. An aluminium cylinder with two cavities is weighed
and its mass, m is recorded. 2. The electrical power of the heater,
P is recorded. 3. The electrical heater is then placed inside the
large cavity in the centre of the cylinder. 4. The thermometer is
then placed in the small cavity of the aluminium cylinder. 5. A few
drops of lubricating oil are added to both cavities to ensure good
thermal
contact (better heat transfer). 6. The apparatus is set up as
shown in the diagram above. 7. The initial temperature of the
aluminium cylinder, 1 is recorded. 8. The electric heater is
switched on and the stopwatch is started simultaneously. 9. After
heating for t seconds, the heater is switched off. The highest
reading on the
thermometer, 2 is recorded. 10. The experiment is repeated and
an average value of c is calculated.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 32 of 52
Results: Electric power of heater = P Watt Heating time = t
seconds Mass of aluminium cylinder = m kg Initial temperature of
the aluminium cylinder = 1 Final temperature of the aluminium
cylinder = 2 Temperature rise = 2 1 Electrical energy supplied by
the heater = Pt Heat energy absorbed by the aluminium cylinder = mc
On the assumption that there is no heat loss to the surroundings:
Heat supplied = Heat absorbed Pt = mc
Specific heat capacity, c = mPt
Discussion: The aluminium cylinder is wrapped with a felt cloth
to reduce the heat loss to the
surroundings and the polystyrene sheet acts as a heat insulator
to avoid heat loss to the surface of the table.
The value of the specific heat capacity of aluminium, c
determined in the experiment is larger than the standard value.
This is because there will be some heat lost to the
surrounding.
The temperature of the aluminium cylinder will continue to rise
after the electrical heater has been switched off because there is
still some heat transfer from the heater to the cylinder.
Conclusion: The specific heat capacity of aluminium is a
constant. 4.2 SPECIFIC LATENT HEAT Experiment 1: Heating of
naphthalene Hypothesis: During the change of state of naphthalene
from solid to liquid, there is no change in temperature when heat
is continuously supplied Aim of the experiment: To observe the
change in temperature when naphthalene is melting Apparatus and
Materials: Boiling tube, naphthalene powder, beaker, thermometer,
Bunsen burner, stopwatch, retort stand, tripod stand, wire
gauze
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Chapter 4: Heat and Energy Page 33 of 52
Set up:
Procedure: 1. The apparatus is set up as shown in the diagram.
2. The initial temperature of the naphthalene is recorded. 3. The
Bunsen burner is lighted and the stopwatch started. 4. The
temperature of the naphthalene is recorded at 1 minute intervals
until the
temperature reaches 100C. 5. The state of the naphthalene is
observed and tabulated throughout the heating process. 6. A graph
of temperature against time is drawn. Results:
Time, t (minute) Temperature of naphthalene, (C) 0 1 2 3
Graph of temperature against time:
Discussion: The temperature-time graph shows that the
temperature of naphthalene rises until the
naphthalene starts to melt. The naphthalene starts to melt at
80C. The temperature remains constant at this value
for several minutes while the naphthalene continues to melt with
the heat.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 34 of 52
After the naphthalene has completely melted, the temperature
begins to rise with continued heating.
Conclusion: The temperature of the naphthalene remains constant
during a change of state from solid to liquid. Experiment 2:
Cooling of naphthalene Hypothesis: During the change of state of
naphthalene from liquid to solid, there is no change in temperature
Aim of the experiment: To observe the change in temperature when
naphthalene is freezing Apparatus and Materials: Boiling tube,
naphthalene powder, beaker, thermometer, Bunsen burner, stopwatch,
retort stand, tripod stand, wire gauze Set up:
Procedure: 1. The apparatus is set up as shown in the diagram.
2. The naphthalene is heated until the temperature reaches 95C. 3.
The boiling tube is then removed from the water bath and the outer
part of the tube is
dried. 4. The temperature of the naphthalene is recorded every
minute until the temperature
drops to about 60C. 5. A graph of temperature against time is
drawn.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 35 of 52
Results: Time, t (minute) Temperature of naphthalene, (C)
0 1 2 3
Graph of temperature against time:
Discussion: The temperature-time graph shows that the
temperature of naphthalene drops until
80C where it stays constant for several minutes as it freezes.
After the naphthalene has completely frozen, the temperature
continues to drop. Conclusion: The temperature of the naphthalene
remains constant during a change of state from liquid to solid.
Experiment 3: Latent heat of fusion (ice) Aim of the experiment: To
determine the latent heat of fusion of ice Apparatus and Materials:
Pure ice, electric immersion heater, filter funnel, beaker,
stopwatch, weighing balance, power supply, retort stand, clamp
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 36 of 52
Set up:
Set A Set B
Procedure: 1. The mass of two empty beakers, A and B are
determined using the weighing balance. 2. The apparatus is arranged
as shown in the diagram above. 3. Each of the two filter funnels is
filled with ice cubes. 4. The immersion heater in Set A, the
control experiment, is not connected to the power
supply. The purpose of Set A is to determine the mass of the ice
melted by the surrounding heat. The heater in Set B is switched
on.
5. When water starts to drip from the filter funnels at a steady
rate, the stopwatch is started and the empty beakers A and B are
placed beneath the filter funnels.
6. After a period of t seconds, the heater B is switched off.
The masses of both beakers, A and B are determined using the
weighing balance.
7. The experiment is repeated to get an average value. Results:
Set A: Mass of empty beaker = mA1 kg Mass of beaker + water = mA2
kg Mass of ice melted by surrounding heat, ma = mA2 mA1 kg Set B:
Mass of empty beaker = mB1 kg Mass of beaker + water = mB2 kg Mass
of ice melted by surrounding heat & immersion heater, mb = mB2
mB1 kg Mass of ice melted by the electric immersion heater, m = mb
ma kg Electrical energy supplied by the electrical immersion
heater, E = Pt Heat energy absorbed by the ice during melting, Q =
mL Assuming there is no heat loss to the surroundings: Electrical
energy supplied = Heat energy absorbed by the melting ice Pt =
mL
Specific latent heat of fusion of ice, L = mPt
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 37 of 52
Discussion: The purpose of Set A, the control experiment, is to
determine the mass of ice melted
by the surrounding heat. The immersion heater must be fully
immersed in the ice cubes to avoid or reduce heat
loss. The stopwatch is not started simultaneously when the
immersion heater is switched
on because the immersion heater requires a time period before
reaching a steady temperature. At this point, the rate of melting
of ice will be steady.
The value of the specific latent heat of fusion of ice, L
obtained in this experiment is higher than the standard value
because part of the heat supplied by the heater is lost to the
surroundings.
Conclusion: The specific latent heat of fusion of ice is a
constant. Experiment 4: Latent heat of vapourisation (water) Aim of
the experiment: To determine the latent heat of vapourisation of
water Apparatus and Materials: Pure water, electric immersion
heater, filter funnel, beaker, stopwatch, weighing balance, power
supply, retort stand, clamp Set up:
Procedure: 1. The apparatus is set up as shown in the diagram
above. 2. A beaker is placed on the platform of the electronic
weighing balance. 3. The electric heater is fully immersed in the
water and held in this position by being
clamped to a retort stand. 4. The electric heater is switched on
to heat the water to its boiling point. 5. When the water starts to
boil at a steady rate, the stopwatch is started and the reading
on the electronic balance, m1 is recorded. 6. The water is
allowed to boil for a period of t seconds. 7. At the end of the
period of t seconds, the reading on the electronic balance, m2
is
recorded.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 38 of 52
Results: Electrical power of heater = P Watt Time period of
boiling = t seconds Electrical energy supplied by the electrical
immersion heater, E = Pt Mass of water vapourised = m2 m1 Heat
energy absorbed by the water during vapourisation, Q = mL Assuming
there is no heat loss to the surroundings: Electrical energy
supplied = Heat energy absorbed by the vapourized water Pt = mL
Specific latent heat of vapourization of water, L = mPt
Discussion: The immersion heater must be fully immersed in the
water to avoid or reduce heat
loss. The stopwatch is not started simultaneously when the
immersion heater is switched
on because the immersion heater requires a time period before
reaching a steady temperature. At this point, the rate of heating
of water will be steady.
The value of the specific latent heat of vapourization of water,
L obtained in this experiment is higher than the standard value
because part of the heat supplied by the heater is lost to the
surroundings.
Conclusion: The specific latent heat of vapourization of water
is a constant. 4.3 BOYLES LAW Option 1: Changing the volume of air
to measure pressure Hypothesis: When the volume of air decreases,
the pressure increases when its mass and temperature is constant
Aim: To investigate the relationship between the pressure and
volume of air Variables: Manipulated: Volume of air within syringe
Responding: Pressure of air Constant: Mass, temperature of air
Apparatus and Materials: Rubber hose, Bordon gauge, 100 cm3
syringe
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 39 of 52
Set up:
Procedure: 1. Apparatus is set up as per the diagram. 2. The
nose of the syringe is fitted with a rubber hose and the piston is
adjusted so that
air volume of 100 cm3 at atmospheric pressure is trapped in the
syringe. 3. The rubber hose is connected to a Bourdon gauge and air
pressure is read from the
gauge. 4. The piston of the syringe is pushed in until the
trapped air volume becomes 90 cm3
and the air pressure is read from the Bourdon gauge. 5. Step 4
is repeated for air volume values 80, 70, and 60 cm3. Results:
Volume, V (cm3) V1 (cm-3) Pressure, P (Pa)
100 90 80 70 60
Analysis:
A graph of P against V1 is plotted.
A linear graph going through the origin is obtained. This
indicates that pressure is inversely proportional to
the volume of gas. Conclusion: Gas pressure of fixed mass is
inversely proportional to its volume.
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Chapter 4: Heat and Energy Page 40 of 52
Option 2: Changing the pressure of air to measure volume
Hypothesis: When the pressure of air decreases, the volume
increases when its mass and temperature is constant Aim: To
investigate the relationship between the pressure and volume of air
Variables: Manipulated: Pressure of air Responding: Volume of air
trapped in the capillary tube Constant: Mass, temperature of air
Apparatus and Materials: Bicycle pump, ruler, tank with oil,
pressure gauge, glass tube Set up:
Procedure: 1. The apparatus is set up as shown in the diagram
above. 2. The piston of the bicycle pump is pushed in to compress
the air inside the glass tube
until the pressure is 10 kPa. 3. When the reading on the
pressure gauge is P, the volume of the air column, V is
recorded. 4. Steps 1 and 2 are repeated for 5 pressure readings
of 20 kPa, 30 kPa and 40 kPa.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 41 of 52
Results: Pressure, P (kPa)
P1 (Pa-1) Volume, V (cm
3)
10 20 30 40
Analysis:
A graph of V against P1 is plotted.
A linear graph going through the origin is obtained. This
indicates that pressure is inversely proportional to the
volume of gas. Conclusion: Volume of gas of fixed mass is
inversely proportional to its pressure. 4.4 CHARLES LAW Hypothesis:
When the temperature of air increases, the volume increases if the
mass and pressure is constant Aim: To investigate the relationship
between the volume and the temperature of gas Variables:
Manipulated: Air temperature Responding: Air volume Constant: Mass
and pressure of the trapped air Apparatus and Materials: Capillary
tube, tall beaker, thermometer, Bunsen burner, tripod, wire gauze,
retort stand, mercury or concentrated sulphuric acid, stirrer,
ruler, ice, rubber band
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 42 of 52
Set up:
Procedure: 1. Apparatus is set up as per the diagram. 2. The air
to be studied is trapped in a capillary tube by concentrated
sulphuric acid. 3. The capillary tube is fitted to a ruler using
two rubber bands and the bottom end of
the air column is ensured to match the zero marking on the
ruler. 4. Water and ice is poured into the beaker until the whole
air column is submerged.
Water is then stirred until the temperature rises to 10 C. The
length of the air column and the temperature of the water are
recorded.
5. Water is heated slowly while being stirred continuously. The
length of the air column is recorded every 10 C until the water
temperature reaches 90 C.
Results: Temperature, (C) 10 20 30 40 50 60 70 80 90 Length of
air column, x (cm) Analysis: A graph of x against is plotted. A
linear graph is obtained. When extrapolated, length x = 0 occurs
when gas temperature, = -273 C
When the Celsius scale is replaced with the Kelvin scale, a
linear graph that goes through origin is obtained.
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Chapter 4: Heat and Energy Page 43 of 52
Discussion: From the graph plotted, it is found that the length
of the air column, x is directly proportional to its temperature, T
(K). Because gas volume is directly proportional to the length of
the column, it also indicates that gas volume is directly
proportional to its absolute temperature. Conclusion: Gas volume of
fixed mass is directly proportional to its absolute temperature 4.5
PRESSURE LAW Hypothesis: When the temperature of air increases, the
pressure increases if the mass and volume is constant Aim: To
investigate the relationship between the pressure and the
temperature of gas Variables: Manipulated: Air temperature
Responding: Air pressure Constant: Mass and volume of the trapped
air Apparatus and Materials: Round-bottomed flask, mercury
thermometer, Bourdon gauge, Bunsen burner, tripod, wire gauze,
retort stand, stirrer, ice Set up:
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 4: Heat and Energy Page 44 of 52
Procedure: 1. Apparatus is set up as per the diagram. 2. The
round-bottomed flask is submerged in water and the water bath with
ice is stirred
continuously until the temperature of the water bath is stable.
3. The temperature of the water is taken from the thermometer. 4.
The reading from the Bourdon gauge is read at temperatures 30, 40,
50, 60, 70 and 80
C. Results: Temperature, (C) 30 40 50 60 70 80Air pressure, P
(Pa) Analysis: A graph of P against is plotted. A linear graph is
obtained. When extrapolated, pressure P = 0 occurs when gas
temperature, = -273 C
When the Celsius scale is replaced with the Kelvin scale, a
linear graph that goes through origin is obtained.
Conclusion: Gas pressure of fixed mass is directly proportional
to its absolute temperature
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 5: Light and Vision Page 45 of 52
CHAPTER 5: LIGHT AND VISION 5.1 REFLECTION Hypothesis: The angle
of reflection is equal to the angle of incidence Aim of the
experiment: To study the relationship between the angle of
incidence and angle of reflection Variables: Manipulated: Angle of
incidence, i Responding: Angle of reflection, r Constant: Plane
mirror used Apparatus/Materials: Light box, plane mirror,
plasticine, paper, pencil, protractor Setup:
Procedure: 9. A straight line, PQ is drawn on a sheet of white
paper. 10. The normal line, ON is drawn from a point at the centre
of PQ. 11. With the aid of a protractor, lines at angles of
incidence 15, 30, 45, 60 and 75 to
the normal line, are drawn to its left. 12. A plane mirror is
erected along the line PQ. It is secured in this position with the
aid
of plasticine. 13. A ray of light from the ray box is directed
along the 15 line. Two positions are
marked with a pencil on the line of the reflected ray. 14. Step
5 is repeated for the other angles of incidence. 15. The plane
mirror is removed. The reflected rays are drawn by joining the
respective
marks. 16. The angles of reflection corresponding with all the
angle of incidence are measured.
The results are tabulated.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 5: Light and Vision Page 46 of 52
Results: Incident angle () Reflected angle ()
15 30 45 60 75
Conclusion: The angle of incidence is equal to the angle of
reflection. 5.2 CURVED MIRRORS Aim of the experiment: To study the
characteristics of images formed by curved mirrors
Apparatus/Materials: Concave mirror, convex mirror, plasticine,
light bulb mounted on a wooden block, metre rule, white screen
Setup:
Procedure: 1. The apparatus is set up as shown in the diagram.
2. The focal length, f and the radius of curvature, r of the
concave mirror, as supplied,
are recorded. 3. The light bulb is positioned at a distance
greater than the radius of curvature of the
mirror, i.e. u > 2f. The white screen is moved between the
concave mirror and the light bulb until an image is clearly focused
on the screen. The image distance, v is measured by a metre rule
and recorded.
4. Step 3 is repeated with the light bulb positioned at C (u =
2f), between C and F (f < u < 2f), at F (u = f), and between
F and P (u < f).
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 5: Light and Vision Page 47 of 52
5. The values of u, v, and the characteristics of the images
formed are recorded in a table.
6. The experiment is repeated by replacing the concave mirror
with a convex mirror. Results: Concave mirror;
Characteristics of image Position of object
Object distance, u
(cm)
Image distance, v
(cm) Real /
Virtual Upright / Inverted
Diminished / Magnified / Same
size Beyond C
(u > 2f)
At C (u = 2f)
Between C and F
(f < u < 2f)
At F (u = f)
Between F and P
(u < 2f)
Convex mirrors: For all positions, the image characteristics
are: __________________________ Conclusion: For concave mirrors,
images formed can be real or virtual, whereas for convex
mirrors, only virtual images are formed. The characteristics of
images formed by the concave mirror depend on the position of
the object. 5.3 REFRACTION Hypothesis:
The refracted light ray obeys Snells Law which states that the
value of ri
sinsin is a
constant where i is the angle of incidence and r is the angle of
refraction Aim of the experiment: To study the relationship between
the angle of incidence and angle of refraction
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 5: Light and Vision Page 48 of 52
Variables: Manipulated: Angle of incidence, i Responding: Angle
of refraction, r Constant: Plane mirror used Apparatus/Materials:
Ray box, glass block, paper, pencil Setup:
Procedure: 1. The outline of the glass block is traced on a
sheet of white paper and labeled. 2. The glass block is removed.
Point O is marked on one side of the glass block. With a
protractor, lines forming angles of incidence 20, 30, 40, 50 and
60 are drawn and marked.
3. The glass block is replaced on its outline on the paper. 4. A
ray of light from the ray box is directed along 20 line. The ray
emerging on the
other side of the block is drawn. 5. Step 4 is repeated for the
other angles of incidence. 6. The glass slab is removed. The points
of incidence and the corresponding points of
emergence are joined. The respective angles of refraction are
measured with a protractor.
7. The values of sin i, sin r, and ri
sinsin are calculated.
Results:
Angle of incidence, i () Angle of refraction, r () Sin i Sin r n
= ri
sinsin
20 30 40 50 60
Conclusion:
It is found that ri
sinsin is a constant. Hypothesis valid.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 5: Light and Vision Page 49 of 52
5.4 ACTUAL DEPTH & APPARENT DEPTH Hypothesis: The deeper the
actual depth, the deeper the apparent depth Aim of the experiment:
To study the relationship between the actual depth and apparent
depth Variables: Manipulated: Actual depth, D Responding: Apparent
depth, d Constant: Refractive index of medium (water), n
Apparatus/Materials: Tall beaker, 2 pins, ruler, metre rule, retort
stand Setup:
Procedure: 1. Apparatus is set up as shown in the diagram. 2. A
pin is mounted on a movable clamp on a retort stand. 3. Another pin
is placed at the base of the tall beaker. Water is filled as the
actual depth
to D = 7.0 cm. 4. The object pin O is observed from the top, and
pin I is adjusted vertically until it
appears to meet pin O. At this point, the position of pin I
matches the apparent depth, d of pin O. The apparent depth is
measured from the top of the water level to the position of pin
I.
5. Step 4 is repeated by changing the actual depth to 9.0 cm,
11.0 cm, 13.0 cm and 15.0 cm.
6. The results are tabulated and a graph of D against d is
plotted.
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 5: Light and Vision Page 50 of 52
Results: Actual depth, D (cm) Apparent depth, d (cm)
7.0 9.0 11.0 13.0 15.0
Analysis: A linear graph that goes through origin is
obtained.
Discussion: The gradient of the graph is equal to the index of
refraction of water. Conclusion: Hypothesis is valid 5.5 TOTAL
INTERNAL REFLECTION Aim of the experiment: To determine the
critical angle of glass Apparatus/Materials: Semicircular glass
block, ray box, protractor, white paper, pencil Setup:
Procedure: 1. A semicircular glass block is placed on a sheet of
white paper. The outline of the
glass block is traced onto the paper with a sharp pencil.
d
D
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Chapter 5: Light and Vision Page 51 of 52
2. The glass block is put aside. A normal line, NN is drawn
through the centre point, O on the diameter.
3. The glass block is replaced on its outline. 4. A narrow beam
of light from the ray box is directed at point O at a small angle
of
incidence. The refracted and reflected rays are observed. 5. The
angle of incidence, i measured from the normal line is adjusted
until the light ray
is refracted along the length of the air-glass boundary. The
point of entry of the light ray is marked and measured with a
protractor. At this point, the incident angle is known as the
critical angle, c.
6. The angle of incidence is increased and the resultant rays
are observed. 7. The experiment is repeated by pointing the light
ray through the other side of the
semicircle. Results: When i < c, part of the light ray is
refracted to the air, and part of it will be reflected
back within the glass block When i = c, the light ray will be
refracted along the length of the glass-air boundary When i > c,
no refraction occurs; all the light ray will be totally internally
reflected
within the glass block Analysis: The critical angle, c is a
constant.
Refractive index of glass, n = csin
1
Conclusion:
The refractive index of glass, n = csin
1
5.6 LENSES Hypothesis: The image produced by a convex lens is
virtual or real depending on the position of the object. The
characteristics of an image produced by a concave lens is not
affected by the object distance. Variables: Manipulated: Object
distance, u Responding: Image distance, v Constant: Focal length of
lens, f Apparatus/Materials: Cardboard with a cross-wire in
triangular cut-out, light bulb, lens holder, convex lens, concave
lens, white screen
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008
Chapter 5: Light and Vision Page 52 of 52
Setup:
Procedure: 1. The apparatus is set up as shown in the diagram.
2. The focal length, f of the convex lens supplied is recorded. 3.
The object (triangle with a cross-wire) is placed at a distance
greater than 2f from the
convex lens. 4. The white screen is moved back and forth until a
sharp image of the triangle is
formed on the screen. The image distance, v is measured. The
characteristics of the image are observed and recorded in a
table.
5. Step 3 is repeated wit the object distances, u = 2f, f < u
< 2f, u = f, and u < f. 6. For positions where the image
cannot be formed on the screen, the screen is removed
and the image is viewed through the lens from the other side of
the lens. 7. The experiment is repeated by replacing the convex
lens with a concave lens. Results: Convex lens:
Characteristics of image Position of object
Object distance, u
(cm)
Image distance, v
(cm) Real /
Virtual Upright / Inverted
Diminished / Magnified / Same
size u > 2f u = 2f
f < u < 2f u = f u < 2f
Concave lens: For all positions, the image characteristics are:
__________________________ Conclusion: For convex lenses, images
formed can be real or virtual, whereas for concave lenses,
only virtual images are formed. The characteristics of images
formed by the convex lens depend on the position of the
object.