Question

A rocking chair is an example of:
A) Periodic motion
B) Translatory motion
C) Rotatory motion
D) None of the above

Answer 1

Hint: The rocking chair repeats its motion continuously on the same path it moves back and forth direction so from this we can guess what type motion is this called when a body repeats its motion on the same path in a fixed interval of time.

Complete step by step solution:
There are some types of motion we discuss here about the motion which are given in our option in this question.
Let’s talk about the first option. First option is periodic motion:
The periodic motion is defined as when an object repeats its motion at an equal interval of time then the motion is called periodic motion means in the same interval of time the object repeats its motion on the same path. There are some examples of periodic motion the earth revolving in its orbit around the sun in 365 days. It is a periodic motion and time period of motion is 365 days.
A simple pendulum moves to and fro motion between its 2 extreme points this motion is also called periodic motion.

The second option translatory motion:
Whenever a body change its position or its place with time in a straight line then it is called translation motion Or Translational motion is motion that involves the sliding of an object in one or more of the three dimensions: x, y or z

Option three is rotatory motion:
The Rotatory motion or rotational motion is defined as when an object spins around an internal axis in a continuous way. An ice-skater can do this by spinning on the spot.
So from above explanation we can understood the rocking chair repeat its motion in a equal interval of time so Motion of rocking chair is periodic motion

Hence option A is correct here.

Note: Sometimes students get confused rocking chairs make oscillatory motion why we mark option periodic motion. Periodic motion object repeats its path in a fixed interval time and in oscillatory motion objects move to and fro and repeat this path in fixed intervals of time. Means every oscillatory motion is a periodic motion but every periodic motion is not an oscillatory motion.