1. A 50kg crate is pulled 40m along a horizontal floor by a constant force exerted by a person, Fp=100N, which acts at a 37 degree angle. The floor is rough and exerts a friction force Ff= 50N. Determine the work done by each force acting on the crate (including normal force and force of weight), and the net work done on the crate. W=F*d*cos( angle ) 3. no idea how to do it.