Question

State whether true or false.
Motion of a child on a swing is periodic motion.
A. True
B. False

Answer 1

Hint: If you ever noticed the motion of a pendulum, you may know that its to and fro motion repeats itself. This type of motion where the motion repeats itself after every equal interval of time is called a periodic motion.

Complete step by step answer:

Let us first understand what it is meant by a periodic motion. We all know what a motion is. By motion of a body, we understand that the body is in motion. Different bodies move in different types of motion.
One of the many types of motion is rectilinear motion or straight-line motion. By the word, straight line you will know that it is a motion of a body moving in a straight line. It can be a uniform motion or a non-uniform motion depending on the factors affecting its motion.
When a body moves in a circular path, then its motion is said to be a circular motion. If the body is moving with constant speed i.e. distance moved by the body in one unit of time, then its motion is called uniform circular motion.
Sometimes, the motion of a body repeats itself. For example, the motion of a pendulum. If you ever noticed the motion of a pendulum, you may know that its to and fro motion repeats itself. This type of motion where the motion repeats itself after every equal interval of time is called a periodic motion.
Now, we will be able to answer whether the motion of a child on a swing is a periodic motion. If you have noticed, the motion of a swing is the same as that of a pendulum. We know that the motion of a pendulum is periodic. Therefore, the motion of a swing is periodic. This further implies that the motion of the child is a periodic motion.
Hence, the given statement is true.

Note: Under periodic motion, there are other types of motion. Back and forth motion of an object such as the pendulum is also called oscillatory motion. One back and forth motion is called one complete cycle or oscillation.
When in an oscillatory motion, the acceleration of the object is directly proportional to the displacement of the object from the mean position, the motion is called simple harmonic motion.