Question

In a downhill ski race, surprisingly, little advantage is gained by getting a running start. (This is because the initial kinetic energy is small compared with the gain in gravitational potential energy even on small hills.) To demonstrate this, find the final speed in m/s and the time taken in seconds for a skier who skies 63.0 m along a 27° slope neglecting friction for the following two cases. (Enter the final speeds to at least one decimal place.) (a) starting from rest final speed m/s time taken s (b) starting with an initial speed of 3.50 m/s final speed m/s time taken s (c) Does the answer surprise you? Discuss why it is still advantageous to get a running start in very competitive events.

Answer 1

(a)

(Conservation of energy)

(b)

(Conservation of energy)

(c) Yes, it surprises me. Since there is not a very significant increase in the final speed even if the skier starts with some initial velocity rather than from rest.

But if we compare the time taken, we can see if the skier starts with some initial velocity, it takes less time to get to the bottom of the hill as compared to starting from the rest case. So it's advantageous to get a running start in very competitive events since time is very crucial in these events.