The skier covered a 100 m slope in 20 s, moving at an accelerated rate of 0.3 m / s.

The skier covered a 100 m slope in 20 s, moving at an accelerated rate of 0.3 m / s. What is the speed of the skier at the beginning and end of the slope?

Problem data: S (slope length, skier’s path) = 100 m; t (duration of descent) = 20 s; a (skier acceleration) = 0.3 m / s2.
1) The speed of the skier at the beginning of the descent: S = V0 * t + 0.5 * a * t ^ 2, whence V0 * t = S – 0.5 * a * t ^ 2 and V0 = (S – 0.5 * a * t ^ 2) / t = (100 – 0.5 * 0.3 * 20 ^ 2) / 20 = 2 m / s.
2) Speed at the end of the descent: V = V0 + a * t = 2 + 0.3 * 20 = 2 + 6 = 8 m / s.
Answer: The speed of the skier at the beginning of the slope was 2 m / s, the speed at the end of the descent was 8 m / s.