Friction: Kieran takes off from rest down a 50 m high, 10° slope on his jet-powered skis. The skis have a thrust of 280 N parallel to the surface of the slope. The combined mass of skis and Kieran is 50 kg (the fuel mass is negligible). Kieran's speed at the bottom is 40 m/s. What is the coefficient of kinetic friction of his skis on snow?
A) 0.47
B) 0.58
C) 0.23
D) 0.29

Question

Quizplus · Accepted Answer

The work done by friction is equal to the difference in kinetic energy at the top and bottom of the slope, minus the work done by the thrust. The coefficient of kinetic friction is then found to be 0.47.

Friction: Kieran Takes Off from Rest Down a 50 M