You are provided with a uniform meter rule, a knife edge, masses and other necessary apparatus.

1. Suspend the metre rule horizontally on the knife edge. Read and record the point of balance G of the métre rule. Keep the knife edge at this point throughout the experiment.
2. Using the thread provided, suspend the object labelled W at the 15cm mark of the metre rule.
3. Suspend a mass M= 20g on the other side of G. Adjust the position of the mass until the metre rule balances horizontally again.
4. Read and record the position Y of the mass M on the metre rule.
5. Determine and record the distance L between the mass and G. Also determine and record the distance D between W and G.
6. Repeat the procedure for four other values of M = 30, 40, 50 and 60 g. In each casse ensure that W is kept Constant at the 15 cm mark and the knife edge at G.
7. Evaluate L\(^{-1}\) in each case. Tabulate your readings.
8. Plot a graph of M on the vertical axis against L\(^{-1}\) on the horizontal axis.
9. Determine the slope S, of the graph.
10. Evaluate \(\frac{4}{D}\)

State two precautions taken to obtain accurate results.
(b)i. State the principle of moments.

ii. Define centre of gravity