일반물리학 1 — Potential Energy and Conservation of Energy: Problem 50

50 A 60 kg skier leaves the end of a ski-jump ramp with a velocity of 27 m/s directed 25° above the horizontal. Suppose that as a result of air drag the skier returns to the ground with a speed of 22 m/s, landing 14 m vertically below the end of the ramp. From the launch to the return to the ground, by how much is the mechanical energy of the skier–Earth system reduced because of air drag?