A small block with mass 0.0500kg slides in a vertical circle of radius 0.450m on the inside of a circular track. Through one of the revolutions of the block, when the block is at the bottom of its path, point A, the magnitude of the normal force exerted on the block by the track has magnitude 3.85N. In this same revolution, when the block reaches the top of its path, point B, the magnitude of the normal force exerted on the block has magnitude 0.690N
How much work was done on the block with friction during the motion of the block from point A to point B?