Question

what is force exerted by an object which at rest and have mass 5 kg

Answer 1

F = ma (magnitude-wise) so if the force applied on the body is 10N, 10 N = 5 kg × a m/s², ‘a’ being the acceleration of the body, a = F/m = 10÷5 = 2 m/s². Note that the acceleration produced in the body will be in the same direction as the force applied. This is true if the body is at rest or even if it were in motion. However, if in case of a body being in motion, the force applied were in the opposite direction of the motion of the body, it would result in a deceleration, i.e., a negative acceleration, or an acceleration in a direction same as that of the applied force, in this case being in a direction OPPOSITE to the direction of motion of the body.