Question

Give Reasons-
1-Motion that repeats itself after some period of time is periodic motion.

Answer 1

Motion that repeats itself regularly is called periodic motion. One complete repetition of the motion is called a cycle. The duration of each cycle is the period.The motion of a swing repeats itself at a certain time interval. Therefore, it has periodic motion. Hence, a child on a swing is said to have periodic motion.
(iv) Motion of the needle of a sewing machine is periodic.
Periodic motion: