1. The problem statement, all variables and given/known data Ok, I am doing attempting to do a lab report right now and I am unable to find the forces that I need. This is what i am being asked to do: "Plot the force (not mass) applied by the sand versus the force exerted on the track by the block and its load for both the kinetic and static cases with the felt-aluminum interface." All I have are the masses of the two objects. One object(the block) is on a surface while the other(the sand) is hanging over the edge with a pulley. What I think I need is the applied force by the sand and the friction force but not entirely sure how to do that. Any help would be much appreciated.