A traveler takes a trip with a reluctant pack mule. He finds that he has to exert a constant 470 N horizontal force on the mule to keep the mule moving at a constant speed of 0.9 m/s for a distance of 1.8 km across a horizontal plane. Compute the amount of work the (now exhausted) traveler did on this mule during this trip.
d = 1.8km * 1000m/km = 1800m.
W = Fd = 470 * 1800 = 846,000 Joules.