Study Of Physics

Rest And Motion

Rest and motion are relative terms. A person sitting in a moving car is at rest with respect to his or her fellow passengers, but is in motion with respect to other objects or people on the road.

Rest

If a body does not change its position with respect to some observer then it  is said to be in a state of rest with respect to that observer

Motion

If a body continuously changes its position with respect to some observer then it is said to be in state of motion
 

Example

Consider a train standing on a platform .A notices that the train does not change its position with respect to  the building of station , the poles on the station or tea stalls.So the train is in the state of rest
But as soon as the train start moving, the person finds that the train is changing positions continuously with respect to its surrounding