A man pushes a 42 kg crate uphill along a plane inclined at 30 degree with respect to the horizontal. The man pushes the crate with a constant force of 250 N along the incline and the crate moves with constant velocity. If the crate travels a distance of 4.0 m along the incline, find:
1) the work done by the man.
2) the work done by gravity
3) the total work on the crate by dissipative forces such as air resistance.