1. The problem statement, all variables and given/known data A person is dragging a packing crate of mass 100kg across a rough floor where the coefficient of kinetic friction is 0.4. He exerts a force F just sufficient to keep the crate moving at a constant velocity. At what angle above the horizontal should his pulling force F be for it to be minimum? 2. Relevant equations 3. The attempt at a solution Kinetic friction force = 0.4 x 100g = 40g Fcos theta = 40g F sin theta = 100g tan theta = 10/4 theta = 68.1 degree am i right?