In Fig. 8-49, a block slides down an incline. As it moves from point A to point B, which are 3.0 m apart, force acts on the block, with magnitude 3.8 N and directed down the incline. The magnitude of the frictional force acting on the block is 5.3 N. If the kinetic energy of the block increases by 32 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?

Question

In Fig. 8-49, a block slides down an incline. As it moves from point A to point B, which are 3.0 m apart, force  acts on the block, with magnitude 3.8 N and directed down the incline. The magnitude of the frictional force acting on the block is 5.3 N. If the kinetic energy of the block increases by 32 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?

drwls · Answer

Gravity does work equal to the KE increase PLUS the work done aqainst friction. The gravity work should equal the potential energy change

Anonymous · Answer

A 3.0-kg block moves up a 40° incline with constant speed under the action of a 26-N force acting up and parallel to the incline. What magnitude force must act up and parallel to the incline for the block to move down the incline at constant velocity?