Example John pulls a crate having mass 20 kg along a rough horizontal floor with a force of 80 N that is 30 above the horizontal. If the coefficient of friction is 0.25, (a) what is the acceleration and (b) what is the speed after the crate slides 15 m if it starts from rest? 9 Draw a free-body force diagram. 9 Find gravitational force, normal force, and friction. 9 Find the acceleration How much work does John do on the crate as it slides 15 m? How much work does normal force do on the crate as it slides 15 m? How much work does gravity do on the crate as it slides 15 m? How much work does friction do on the crate as it slides 15 m? What is the total work done on the crate as it slides 15 m