Question

How much force is needed to keep an object moving at a constant velocity?

Answer 1

WHEN VELOCITY IS CONSTANT ACCELERATION WILL BE ZERO

THEREFORE FORCE WILL ALSO BE ZERO

MATHEMATICALLY,

force = mass × acceleration = 0 [∵ acceleration = 0]

Answer 2

Zero net force is required to keep an object moving at a constant velocity

• According to Newton's second law, the net external force must be zero in case of zero acceleration
• A moving object will move at constant velocity if the acceleration on the object is zero
• We know that force = mass x acceleration
• Here, since acceleration should be zero, the net external force must also be zero
• If the body is moving without being disturbed by any external force, then no force is needed to be applied to the body for it to travel in constant velocity
• But, if the body has an external force acting on it, we must apply an equal but opposite force on the body to keep it moving in constant velocity
• For example, a rolling ball might decelerate due to friction. Therefore, a force acting opposite to the direction of friction, which has equal magnitude as that of the friction acting upon that ball should be applied to the ball so as to keep it moving in constant velocity