2.  Inference: The period of the oscillation
is depends on the mass of plasticine
 Hypothesis: The bigger the mass the
longer the period of the oscillation
 Aim: To investigate the relationship
between the inertia of the object and
its mass

3.  Variables:
1) Manipulated variable: Mass of the plasticine , m
2) Responding variable: Period of the oscillation, T
3) Fixed variable: The stiffness of jigsaw blade and
the distance of the centre of the plasticine from
the clamp

4.  Apparatus and materials:
Jigsaw blade , stopwatch , plasticine sphere
of different masses and G-clamp

5. 1) Apparatus and materials are setup as shown
in the diagram.
2) A 20g 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,t1is measured using a stopwatch
and recorded.

6. 4) Step (3) is repeated to get t2. The average of
10 complete oscillations, t is calculated.
Then the period of oscillation is determined
,T
5) Step (3) and step (4) are repeated using
plasticine ball with masses 40g , 60g , 80g
and 100g
6) A graph of T2 versus mass of load, m is
drawn

7.  The change in mass and time for 10
oscillations are recorded in the table below:
Mass of Time for 10 Period, T (s) Square
plasticine, m oscillations, t period, T2 (s2)
(g) (s)
t1 t2 t
20.0
40.0
60.0
80.0
100.0

8. 1) From the experiment it is observed that the
bigger the mass of plasticine attached to the
jigsaw blade, the bigger the period of
oscillation of the blade.
2) The period of the oscillation is an indicator
of inertia of the plasticine whereby the bigger
the period of oscillation , the bigger is the
inertia of the plasticine. Hence , the bigger is
the mass of the plasticine , the bigger is its
inertia

9.  The gradient of the graph:
T2
m
m
.......... ... s 2 / g
 From the graph:
When
a) The mass of plasticine = 12 g
Period of oscillation= …………….

10. b) The mass of plasticine = 22 g
Period of oscillation= …………….
c) The mass of plasticine = 52 g
Period of oscillation= …………….

11. Conclusion:
Object with a larger mass has larger inertia
 Precautions:
1) The jigsaw blade must be horizontal.
2) Make sure the plasticine ball is oscillating in
the same horizontal plane