(a) You are provided with a set of masses, a metre rule, a thread, two retort stands and clamps, a stop watch, a knife edge and split corks.

Carry out the following instructions using the diagram above as a guide.

(i) Determine the centre of gravity, C, of the metre rule using the knife edge.

(ii) Read and record the mass, M, of the metre rule written on the reverse side of it.

(iii) Suspend the metre rule by means of two parallel threads of equal length, h =70 cm, with one at the 10 cm mark and the other at 90 cm mark of the metre rule.

(iv) Attach a mass m = 30g firmly to the metre rule at C. Ensure that the graduated face of the metre rule is facing upwards and that d= 80 cm throughout the experiment. (v) Set the metre rule into small angular oscillations about the vertical axis through its centre of gravity by displacing its ends in opposite directions.

(VI) Determine the time,i, for 20 oscillations and evaluate the period T, T\(^2\) and T\(^{-2}\).

(vii) Repeat the procedure for four other values of m =40 g, 50 g, 60 g and 70 g n each case, determine I and evaluate T\(^2\) and T\(^{-2}\).

(viii) Plot a graph of T on the vertical axis and m on the horizontal axis.

(ix) Determine the slope, s, of the graph.

(x) Evaluate Q= 0.68 / s.

(xi) State two precautions taken to ensure accurate results.

(b) (i) Give two examples of simple harmonic motion other than the motion of a simple pendulum.

(ii) Explain the term centre of gravity of a body.