Page 21 - text book form physics kssm 2020

Chapter 1
Measurement
1. Set up the apparatus as shown in Figure 1.12.
2. Adjust the length of pendulum, l = 20.0 cm.
3. Displace the pendulum bob at an angle of less than 10º from the vertical and release it.
4. Measure and record the time, t taken for 20 complete oscillations.
1
5. Repeat step 4 and record the time as t .
2
(t + t )
6. Calculate the average time, t average = 1 2 2 .
t
2
7. Calculate the period of oscillation, T = average and the value of T .
20
8. Repeat steps 2 to 6 with length of pendulum, l = 30.0 cm, 40.0 cm, 50.0 cm, 60.0 cm
and 70.0 cm.
9. Record the data in Table 1.6.
Results:

Table 1.6
Time for 20 complete
Length of oscillations, t / s 2 2
pendulum, l / cm T / s T / s
1 2 average
t t t
20.0

30.0

40.0

50.0

60.0

70.0

Analysis of data:
1. Plot a graph of T against l and a graph of T against l on separate sheets of graph paper.
2
2. State the shape of the graph and the relationship between the variables in each graph.
2
3. Determine the gradient, m of the graph of T against l. State the value of m in S.I. unit.
Show clearly how you obtain the answer.
4. Given T = 4π 2 l where g is the Earth’s gravitational acceleration.
2
g
Relate gradient, m to the value of g and then determine the value of g in this experiment.
Conclusion:
What conclusion can you make in this experiment?
Prepare a complete report on this experiment.

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1.2.3