The statue of Isaac Newton is crated and moved from the Oxford Museum of Natural History and Science for cleaning. The mass of the statue and the crate is 150kg. As the statue slides down a ramp inclined at 40 degrees, the curator pushes up, parallel to the ramp's surface, so that the crate does not accelerate. If the statue slides 3m down the ramp, and the coefficient of kinetic friction between the crate and the ramp is 0.54, calculate the work done on the crate by each of the following:
(a) the gravitational force,
(b) the curator,
(c) the friction force, and
(d) the normal force between the ramp and the crate.