3. Sally (45 kg) and Stan (90 kg) and arrive at Michigan Adventure and climb the stairs to ride the big Shivering Timber coaster that is nearly 40 m tall and reaches speeds of 65 mi/hr.
a) Compare the potential energies of Sally and Stan as they wait in line at the top of the stairs.
Explain your reasoning.

The drag force, fd, imposed by the surrounding air on a vehicle moving with velocity v is given by fd = cdaρv 2/2 where cd is a constant called the drag coefficient, a is the projected frontal area of the vehicle, and ρ is the air density. an automobile is moving at v = 80 kilometers per hour with cd = 0.28, a = 2.3 m2, and ρ = 1.2 kg/m3.