Question

A heavy box is kept on a smooth inclined plane and is pushed up by a force F acting parallel to the plane. Does the work done by the force F as the box goes from A to B depend on how fast the box was moving at A and B? Does the work by the force of gravity depend on this? 

Answer 1

1. Yes. The work done by F depends only on the magnitude of the force F, the displacement d, and the direction of the force. It does not depend on the speed of the box at points A or B.
2. No, because gravitational force is a conservative force and work done by a conservative force will depend only on the force and the displacement.