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🔬 Activity 8.2 - Let Us Experiment With a Pendulum
Materials needed: String of about 150 cm, a heavy metal ball or stone (bob), a stopwatch, a ruler.
Procedure:
- Tie the bob at one end of the string.
- Fix the other end to a rigid support such that the string is about 100 cm long.
- Wait for the bob to come to rest.
- Move the bob slightly to one side and release it gently.
- Measure the time taken for 10 oscillations .
- Repeat 3–4 times.
- Divide the total time by 10 to get the time period.
Observation: The time period stays almost the same every time.
Explanation: A pendulum of a given length always takes the same time for one oscillation. This is why pendulums measure time accurately.
We measure 10 oscillations and divide by 10 to reduce errors in starting and stopping the watch.
