17
Paper 3 2005
Section A
1.
A student carries out an experiment to study the relationship between the speed, v,
of a trolley with the distance of compression, e, of a spring that pushes the trolley
down a track.
A piece of ticker tape is fixed to the trolley which is placed on a friction compensated
track. The trolley is pushed back to compress the spring to a distance of
compression, e, equal to 2.0 cm. as shown in Figure 1.1. The trolley is then released
and it moves down the track with speed v.
A section of the ticker tape which represents the movement of the trolley when it
reached the end of the track, is taken. The actual size of the ticker tape is shown in
Figure 1.2 .
The above procedure is repeated by varying the values of e, to be 30.0 cm, 40.0 cm,
50.0 cm and 60.0 cm. The actual sizes of the sections of the ticker tapes are shown
in Figures 1.3, 1.4, 1.5 and 1.6 respectively.
18
The speed, v, when the trolley reached the end of the track can be calculated using
he formula below;
where, x is length for 10 ticks as shown in Figure 1.7. One tick is the time taken for
the trolley to move between two consecutive dots.
FIGURE 1.7
Figures 1.2 and 1.3 show the actual lengths of the ticker tapes.
x = .............................. cm
Distance of compression, e = 2.0 cm
Figure 1.2
x = .............................. cm
Distance of compression, e = 3.0 cm
Figure 1.3
19
Figures 1.4, 1.5 and 1.6 show the actual lengths of the ticker tapes.
x = .............................. cm
Distance of compression, e = 4.0 cm
Figure 1.4
x = .............................. cm
Distance of compression, e = 5.0 cm
Figure 1.5
x = .............................. cm
Distance of compression, e = 6.0 cm
Figure 1.6
20
(a) For the experiment described on page 5, identify;
(i) the manipulated variable,
....................................................................................................................................
[1 mark]
(ii) the responding variable,
....................................................................................................................................
[1 mark]
(iii) a fixed variable.
..................................................................................................................................
[1 mark]
(b) Using the method shown in Figure 1.7 on page 5, determine x, for every ticker
tape on Figures 1.2, 1.3, 1.4, 1.5 and 1.6.
(i) Measure x for every ticker tape on Figures 1.2, 1.3, 1.4, 1.5 and 1.6.
Write the values of x on the spaces provided on pages 6 and 7.
(ii) Calculate the values of v for every ticker tape using the formula
Tabulate your results for x and v for every value of e in the space below.
[7 marks]
(c) On the graph paper on page 11, draw a graph of v against e.
[5 marks]
(d) Use your graph in (c), to state the relationship between v and e.
........................................................................................................................................
[1 mark]
21
2 . A student carried out an experiment to investigate the relationship between the
resistance, R, and diameter, d, for a constantan wire, and determine the resistivity, ρ,
of constantan. The student used five constantan wires with different diameters and
fixed the length,l, of each wire as 2x103 mm.
The results of the experiment are shown in the graph R against
FIGURE 2.1
1
in Figure 2.1.
d2
22
(a) State the relationship between R and d2
.......................................................................................................................................
[1 mark]
(b) A constantan wire of unknown diameter has a length of 2 x 103 mm and a resistance
of 0.5 Ω.
Using the graph of R against
1
, determine the diameter of the wire. Show on the
d2
graph how you determined the diameter.
[3 marks]
(c) The resistivity, ρ, of constantan is given by the formula:
 Rd 2 

 l 
  0.786
m

l 
If m = Rd2, then   0.786
where m in is the gradient of the graph of R against
1
d2
(i) Calculate the gradient, m, of the graph of R against
1
d2
Show on the graph how you determined m.
m = ....................................
[3 marks]
23
m
 , calculate the resistivity, ρ of constantan.
l 
(ii) Using the formula,   0.768
Use
l  2  10 3 mm
ρ = ........................................................
[2 marks]
(d) Another constantan wire has a diameter of 2.5 mm and a length of 500 mm. Using
 Rd 2 

 l 
the formula   0.786
and the value of in (c)(ii), calculate the resistance of
the wire.
R = ............................................................
[2 marks]
(e) State one precaution that should be taken during this experiment.
......................................................................................................................................
[1 mark]
24
Section B
3. Before going on a long journey. Shareena measured the air pressure in the tyre of
her car, as shown in Figure 3.1. She found that the air pressure in the tyre was 190
kPa. After the journey, Shareena measured again the air pressure in the tyre as
shown in Figure 3.2. She found that the air pressure in the tyre had increased to 235
kPa. Shareena also found that the tyre became hot after the journey. However the
size of the tyre remained the same.
Using the information on Shareena’s observation on the air pressure in the tyre;
(a) Make one suitable inference.
[1 mark]
(b) State one appropriate hypothesis that could be investigated.
[1 mark]
Design an experiment to investigate the hypothesis stated in (b).
Choose suitable apparatus such as a pressure gauge, a round bottom flask and
others.
In your description, state clearly the following;
(i) aim of the experiment,
(ii) variables in the experiment,
(iii) list of apparatus and materials,
(iv) arrangement of the apparatus,
(v) the procedure of the experiment, which includes the method of controlling the
manipulated variable and the method of measuring the responding variable,
(vi) the way you would tabulate the data,
(vii) the way you would analyse the data.
[10 marks]
25
4. Figure 4.1 shows a cross-section of a bicycle dynamo which has a magnet and a coil
of insulated copper wire. The output of the dynamo is connected to a bicycle lamp.
The lamp will light up when the magnet is rotated by turning the wheel. The light gets
brighter when the wheel turns faster.
Using your knowledge of electromagnetism;
(a) Make one suitable inference. [1 mark]
(b) State one appropriate hypothesis that could be investigated. [1 mark]
(c) Design an experiment to investigate the hypothesis stated in (b).
Choose suitable apparatus such as a bar magnet, a coil of copper wire and others.
In your description, state clearly the following;
(i) aim of the experiment,
(ii) variables in the experiment,
(iii) list of apparatus and materials,
(iv) arrangement of the apparatus,
(v) the procedure of the experiment, which includes the method of controlling the
manipulated variable and the method of measuring the responding variable,
(vi) the way you would tabulate the data,
(vii) the way you would analyse the data.
[10 marks]