Question

A cart for hauling ore out of a gold mine has a mass of 411 kg, including its load. The cart runs along a straight stretch of track that climbs a shallow 4.45∘ incline. A donkey, which is trudging along and to the side of the track, has the unenviable job of pulling the cart up the slope with a 393 N force for a distance of 127 m by means of a rope that is parallel to the slope but makes an angle of 13.3∘ with the track.

Model the rolling resistance of the cart as though it were sliding on the track with a coefficient of friction of 0.0173. Use ?=9.81 m/s^2, and note that angle A in the image is the angle of the incline while angle B is the angle the rope makes with the track.

Find the work W_d that the donkey performs on the cart during this process.

Find the work ?_g that the force of gravity performs on the cart during this process.

Calculate the work ?_f done on the cart by friction during this process.

Answer 1