(a)

You are provided with a retort stand, clamp and boss head, a pendulum bob, a piece of thread, a stop watch and other necessary materials.

(i) Set up the apparatus as illustrated in the diagram above.

(ii) Measure and record the distance **h** = 130 *cm* from the centre of the bob to the point of suspension of the pendulum.

(iii) Displace the pendulum through a small angle and release.

Allow the pendulum to oscillate freely.

(iv) Determine the time, **t** for 20 complete oscillations.

(v) Also determine the period, **T** of the oscillations.

(vi) Evaluate **T2** and **L** = **h** – 30.

(vii) Repeat the procedure for four other values of **h** = 110 *cm*, 90 *c*m, 70 *cm* and 50 *cm* respectively.

(viii) Tabulate your readings.

(ix) Plot a graph with **T**2 on the vertical axis and **L **on the horizontal axis, starting both axes from the origin (0, 0)

(x) Determine the slope, **s**, of the graph and intercept, **e**, on the vertical axis.

(xi) Evaluate:

(α) k1 = __4π2__

s

(b) k2 = [Take π = 3.14]

(xii) State two precautions taken to obtain accurate results.

(b)(i) What is meant by the *period of oscillation* of an oscillating body?

(ii) Explain *acceleration of free* fall due to gravity.