Question

when do we say that a body is at rest and when do we say that it is moving ????

Answer 1

a body is said to be moving when it changes its position with respect to time and surroundings and it is said to be at rest when it does not changes its position with respect to time and surroundings

Answer 2

a body is in rest or in mition totally depend upon the frame or u may say the point of refrence through which you are observing the scenario .....for ex if i am sitting with you in the car... i am in motion wrt to people outside but im in rest wrt to you who is sitting next to me. ...