Question

What do you mean by periodic motion? Give examples. Discuss the type of motion of the hands of a clock. [2 MARKS]

Answer 1

Periodic Motion + Examples: 1 Mark
Hands of clock: 1 Mark

If an object repeats its motion along a certain path, about a certain point, in a fixed interval of time, the motion of such an object is known as periodic motion. Examples of periodic motions are the motion of a pendulum, the motion of a spring, the vibration of a guitar string, the rotation of the Earth about its axis, the revolving of the Earth around the Sun, the revolving of the Sun around the centre of the Galaxy, etc.

The hands of the clock move in a circle about a fixed point. Hence, they definitely perform the circulatory motion. Since the hands of the clock are covering an equal distance in equal interval of times, we can call it a periodic motion.