State of Rest and Motion - Param Himalaya Physics
Definition of Reference point or origin :
A fixed point or a fixed object with respect to which the given body change its position is known as reference point or origin.
There are state of body - 1.Rest 2. motion
1.Rest: A body is said to be in a state of rest when its position does not change with respect to a reference point.
2. Motion : A body is said to be in a state of motion when its position change continuously with respect to a reference point.
Nothing in the universe is at absolute rest.
Type of motion :
1. Linear motion : A body has linear motion of it moves along a straight line or path. Example : Motion of a moving car on a straight road , motion of a ball dropped from the roof of a building.
2. Circular ( Or rotational ) motion : A body has circular motion of it moves around a fixed point.
Example : motion of an electric fan , Motion of merry-go-round , Motion of a spinning top.
" A vertical line passing through the fixed point around which the body moves is known as axis of rotation. "
3. Vibratory motion: A body has vibratory motion if it moves to and fro about a fixed point ( called mean position or equilibrium position).
Example : Motion of a pendulum of a wall clock , Motion of child swinging in a swing , motion of a simple pendulum.
" Rest and motion are relative states. It's means an object which is at rest in one frame of reference can be in motion in another frame of reference at the same time. "