2. To pull a 50-kg crate across a horizontal frictionless floor, a worker applies a force of 210 N, directed at 20° above the horizontal. As the crate moves 3.0

m, what work is done on the crate by (a) the worker, (b)the gravity force acting on the crate, and (c) the normal force on the crate from the floor? (d) What is the total work done on the crate? (6 points)