Suppose the worker in problem no. 1 pushes downward at an angle of 30° below the
horizontal. a) What magnitude of force must the worker apply to move the crate at constant
velocity? b) How much work is done on the crate by this force when the crate is pushed a
distance of 4.5 m? c) How much work is done on the crate by friction during this
displacement? d) How much work is done on the crate by the normal force? By gravity? e)
What is the total work done on the crate?