Q. An observer moving toward Earth with a speed of 0.96 notices that it takes 5.2 for a person to fill her car with gas. Assume, in its place, that the observer had been moving away from Earth with a speed of 0.80.
Q. A rope 100 feet long weighing 2 pounds per foot hangs over the edge of a building 150 feet tall. How much work in foot-pounds is done in pulling the rope to the top of building?