Experiment: Pendulum for measuring time

• Question: Are the swings of a pendulum uniform?
• Aim: To study the relationship between the length of the string and the period of the pendulum to swing 20 times.
• Apparatus: String, stopwatch, nut, scissors and retort stand.

Procedure:

1. Tie a 10 cm string onto the nut to become a pendulum.
2. Swing the pendulum and record the period for the pendulum to swing 20 times.
3. Repeat procedure 1 and 2 with 15 cm, 20 cm and 25 cm strings.
4. Record the observation.

Observation:

The length of the string (cm)                      10           15          20          25

The period for the pendulum
to swing 20 times (second)                         20           25          30          35


Discussion:

1. What is the trend of change for the period of the pendulum to make 20 swings?

          Increase uniformly

     2.  State two variables in the investigation.

          The length of the string used and the period of the pendulum to make 20 swings.

Conclusion: The longer the string, the longer the period for the pendulum to swing 20 times.