Science Practical 7

Measurement of Time - Pendulum

Aim of the Experiment: To determine the relationship between the period and the length of the simple pendulum.

Apparatus: 

120 cm of thread

Pendulum bob

Metre rule

Split cork

Stopwatch

Clamps retort stand

Procedure:

1. Fix one end of the thread to the pendulum bob. Clamp the other end firmly between the split cork, making pendulum of length l = 100.0cm long.

2. Give the pendulum bob a small displacement of between 0 and 10 degrees and set it into oscillation. A complete oscillation is when the bob goes from one end to the other end and back again.

3. Time the period for 10 oscillations using the stopwatch. Record the time as T1. Repeat steps 2 and 3 for another 10 oscillations and record the timing again, but this time record it as T2. Then, find the average of both readings as <t> and hence the periodic time T given by. (T = <t>/10)

4. Shorten length l of the string by pulling on its upper end, and repeat steps 2 and 3 for values of l varying from 90cm to 50cm.

5. Tabulate 6 sets of values of l. T1, T2, <t> and T.

6. Plot a graph of period T against length l.

Conclusion:

The shorter length l is, the less period T will be.