Saturday, 7 May 2011

Form 4 - Chapter 2 Inertia (Experiment)

Essay Question.

In a supermarket, firdaus help his mother to push an empty trolley to carry the things she intends to buy. After shopping, he pushes the trolley which is full to the cashier’s counter. Firdaus noticed that it is more difficult to push full trolley compared to an empty one.
Based on the observation,

a) make one suitable inference,                                                                  [1 mark]
b) state one appropriate hypothesis that could be investigate                      [1 mark]
c) describe how you would design an experiment to test your hypothesis using an inertia balance, G-clamp and other apparatus. In your description, clearly state 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 procedures 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]

Answer :

Option 1:  Using an inertia balance

Inference : Inertia depends on mass

The larger the mass, the bigger the inertia

Aim of the experiment:
To study the effect of mass on the inertia of an object

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.

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.