A small block with mass 0.0475 kg slides in a vertical circle ofradius 0.600 m on the inside of a circular track. During one of therevolutions of the block, when the block is at the bottom of itspath, point A, the magnitude of the normal force exerted on theblock by the track has magnitude 3.90 N . In this same revolution,when the block reaches the top of its path, point B, the magnitudeof the normal force exerted on the block has magnitude 0.680 N.
How much work was done on the block by friction during themotion of the block from point AA to point BB?
