 # Chapter 1 - Measurements

1.

Describe an experiment to show how the period of pendulum can be determined

• The simple pendulum is made to oscillate at a small angle.
• When the oscillation is steady, the time taken for 20 oscillations is measured using a stopwatch.
• The measurement is repeated and the average is calculated.
• The period of the pendulum is given by average time for 20 oscillations divided by 20.

State the precautions you would take for the experiment.

• Ensure that the oscillation is steady before starting to time.
• Ensure that the angular displacement of the bob is less than 10 degrees.

2.

Describe how you would obtain experimentally accurate values for internal (external) diameter of a thick metal pipe.

• Use internal (external) jaws of vernier calipers to measure the internal (external) diameters of the pipe at three different positions.
• Take the average values of the measurements.

Why is there a need to obtain the average of several readings?

• To reduce random errors (the positive errors and negative errors will cancel out)