Question

What's motion? When do you know that a body is in motion or rest?

Answer 1

motion means anything which is in speed.we can identify which body in motion and which in rest by P.E AND K.E of the body.....

Answer 2

 motion is a change in position of an object with respect to time. Motion is typically described in terms of displacement, distance, velocity, acceleration, time andspeed. Motion of a body is observed by attaching a frame of reference to an observer and measuring the change in position of the body relative to that frame.