A cart for hauling ore out of a gold mine has a mass of 445 kg, including its load. The cart runs along a straight stretch of track that is sloped 4.63° from the horizontal. A donkey, trudging along and to the side of the track, has the unenviable job of pulling the cart up the slope with a 537-N force for a distance of 119 m by means of a rope that is parallel to the ground and makes an angle of 13.9° with the track. The coefficient of friction for the cart\'s wheels on the track is 0.0147. Take g = 9.81 m/s2.
a.) Find the work that the force of gravity performs on the cart during the process.
b.) Calculate the work done on the cart during the process by friction.