1. A 9.0-kg box of oranges slides from rest down a frictionless incline from a height of 5.0m. A constant frictional force, introduced at point A, brings the block to rest at point B, 19 m to the right of point A. What is the speed of the block just before it reaches point A? Can anyone point me in the right direction. I'm having a difficult time figuring out where to start solving this problem.