Question

A block slides down an incline. As it moves from point A to point B, which are 5.0 m apart, a force F acts on the block, with magnitude 2.1 N and directed down the incline. The magnitude of the frictional force acting on the block is 10 N. If the kinetic energy of the block increases by 26 J between A and B, how much work is done on the block by the gravitational force as the block moves from A to B?