In a truck loading station at a post office, a small 2.00-kg package is released from rest at point A on a track that is one-quarter of a circle with radius 1.60 m. The size of the package is much less than 1.60 m, so the package can be treated as a particle. It slides down the track and reaches point B with a speed of 4.80 m/s. From point B, it slides on a level surface a distance of 3.00 m to point C, where it comes to rest. a) What is the coefficient of kinetic friction on the horizontal surface? b) How much work is done on the package by friction as it slide down the circular arc from A to B? Normally, I would follow the guidelines and post equations and attempts at this problem but the thing is, I have no idea what equations I'm supposed to use, and that's a bit of a problem. *EDIT* Equations: Fy = -mgy + N I plugged everything in, getting 0 = -(2)(9.8)(cos0) + N and N=19.6. Is this right? What do I do from here, if it is right?