How can we move an object with zero velocity?

Question

Consider there is a box of mass $m$ at rest on the floor. Most books give an example that we need to do a work of $mgh$ to lift the box $h$ upward. If we analyze this work done, the external force acting on the box by us should be equal to the weight of the box. Therefore the net force is zero which in turn there is no acceleration. If there is no acceleration and the initial velocity of the box is also zero, how can the box move upward?

Answer 1

If you lift an object, the work done is the force you exert times the distance you move the object. It just so happens that the force you exert is exactly equal and opposite of the object's weight. Since you are applying a force, there is acceleration (although the initial velocity is zero).