1) The document provides guidance on answering physics questions involving experiments. It suggests including an inference, hypothesis, aim, variables, apparatus, procedure, data table, and graph in the answer. 2) A sample question involves stopping distance and relates mass to inertia. The suggested answer structure includes an inference about mass and inertia, a hypothesis testing their relationship, and an experiment using a jigsaw blade, plasticine balls of varying mass, and a stopwatch. 3) The procedure specifies controlling mass, measuring oscillation period, and repeating with different plasticine masses to obtain data for a graph analyzing the relationship between mass and period.

1. ╞╡§¥ Physics SPM 2013 Physics Paper 3 Answer Guide
Hoo Sze Yen www.physicsrox.com Page 1 of 4
STRUCTURE OF ANSWER
The most important thing when answering this question is to correctly identify the manipulated variable and the
responding variable.
The following answer structure is a suggested guide. Fill in the relevant manipulated and responding variables based on
the question.
(a) Inference
Manipulated variable affects responding variable.
Note: Inference is a cause and effect statement. The inference should be written based on what is observed in the
diagram.
(b) Hypothesis
The greater the manipulated variable, the greater/lower the responding variable.
Note:
 Hypothesis can only investigate physical quantities. Make sure you write out the physical quantity that is being
studied.
 For example: The thinner the wire, the higher the resistance IS WRONG BECAUSE THE PHYSICAL
QUANTITY IS NOT MENTIONED IN THE MANIPULATED VARIABLE.
 Also, avoid using terms like “directly proportional” or ”inversely proportional”. These are conclusions to be made
based on the results and graph.
(c)
(i) Aim
To study the relationship between the manipulated variable and the responding variable.
(ii) Variables
Manipulated variable:
Responding variable:
Constant variable: one is sufficient
Note: Write only physical quantities. Do not write objects.
(iii)Apparatus and materials
Note: You can write the entire list in one line. Ensure you include the measuring instruments to measure the
manipulated variable, the responding variable, and the constant variable (where applicable)
(iv)Arrangement of apparatus
Note: This is the drawing of the setup of the experiment. Draw in pencil COMPLETE WITH LABELS.
Marks allocated: 1
Marks allocated: 1
Marks allocated: 1
Marks allocated: 1
Marks allocated: 1
Marks allocated: 1
Marks allocated: 1

2. ╞╡§¥ Physics SPM 2013 Physics Paper 3 Answer Guide
Hoo Sze Yen www.physicsrox.com Page 2 of 4
(v) Procedure
1. Method to control the manipulated variable – state the initial value of the manipulated variable
2. Method to measure the responding variable
3. Experiment is repeated with 4 more values of the manipulated variable – specify the 4 values!
Note: The values of the manipulated variable MUST BE LOGICAL and can be conducted in a school laboratory.
The repetition of the experiment in step 3 MUST HAVE VALUES. DO NOT write “the experiment is repeated with 4
other values. You will not get marks if you do!
(vi)Tabulation of Data
Manipulated variable (unit) Responding variable (unit)
Fill up with the values specified in
your procedure
(vii) Data Analysis
A graph of responding variable against manipulated variable is plotted
Note: Draw only the axes and label them with the corresponding variables and units. You do not need to plot a
graph, draw a best fit line, or write a title.
Manipulated variable (unit)
Responding
variable (unit)
Marks allocated: 3
Marks allocated: 1

3. ╞╡§¥ Physics SPM 2013 Physics Paper 3 Answer Guide
Hoo Sze Yen www.physicsrox.com Page 3 of 4
SAMPLE QUESTION
A Section B question looks typically like this:
Figure 1(a)
Figure 1(b)
Figure 1(a) shows a small car stopping suddenly after moving at constant speed of
80 km hr-1
when the driver sees the landslide in front of him on the road.
Figure 1(b) shows a big truck that was moving at the same speed, but is not able to stop at a safe distance
when the driver sees the landslide.
Based on the above observations:
(a) State one suitable inference that can be made.
[1 mark]
(b) State one appropriate hypothesis for an investigation.
[1 mark]
(c) Describe an experimental framework to test your hypothesis. Choose appropriate apparatuses such as a
jigsaw blade, plasticine, and other suitable apparatus. 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) Way you would tabulate the data
(vii) Way you would analyse the data
[10 marks]

4. ╞╡§¥ Physics SPM 2013 Physics Paper 3 Answer Guide
Hoo Sze Yen www.physicsrox.com Page 4 of 4
SAMPLE ANSWER
(a) Inference: Mass affects its inertia
(b) Hypothesis: The greater the mass of an object, the greater its inertia
(c) (i) Aim of the experiment: To study the relationship between the mass of an object and its inertia
(ii) Variables:
Manipulated: Mass of plasticine
Responding: Inertia OR period of oscillation
Constant: Stiffness of jigsaw blade OR distance of plasticine ball to clamp
(iii) Apparatus/Materials: Jigsaw blade, G-clamp, stopwatch, and plasticine spheres of mass 20 g, 40 g,
60 g, 80 g, and 100 g
(iv) Arrangement of apparatus:
(v) Procedure:
1. The experiment is setup as shown above.
2. A 20.0 g plasticine sphere 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. The period of oscillation is calculated
using
10
t
T  .
4. The experiment is repeated using plasticine spheres of masses 40.0 g, 60.0 g,
80.0 g, and 100.0 g.
(vi) Tabulation of data:
Mass of plasticine sphere (g) Time for 10 oscillations (s) Period of oscillation (s)
20.0
40.0
60.0
80.0
100.0
(vii) Data analysis:
A graph of period against mass is plotted.
Mass (g)
Period of
oscillation (s)
Method to measure the responding variable
Method to control
the manipulated
variable
Experiment is repeated