(4%) Problem 18: In a downhill ski race, your final velocity is not affected very much by getting a running start, because the initial kinetic energy is small compared with the gain in gravitational potential energy on even small hills. However, you will finish the race much faster (which is more important!). To demonstrate this, find the final speed and the time taken for a skier who skis 77.5 m along a slope that is 24°, measured from horizontal, in the following situations (you may neglect friction).