Question

when an object is said to be at rest​

Answer 1

An object is said to be in rest when it does not change its position with time. If an object changes its position with respect to time it is said to be in motion.

Answer 2

Explanation:

Rest: An object is said to be at rest if it does not change its position with respect to its surroundings with time. Motion: An object is said to be in motion if the position changes with respect to it surrounding and time.