A skier is gliding along at 3.0 m/s on horizontal, frictionless snow. He suddenly starts down a 11 ∘ incline. His speed at the bottom is 15 m/s .

Question

A skier is gliding along at 3.0 m/s on horizontal, frictionless snow. He suddenly starts down a 11 ∘ incline. His speed at the bottom is 15 m/s .

What is the length of the incline?

How long does it take him to reach the bottom?

Answer 1

Change of kinetic energy equel work of force: mv²/2 - mv₀²/2 = mglcos(90° - θ) = mglsinθ; l = (v² - v₀²)/(2gsinθ); l = (15² - 3²)/(2·9.81·sin11°) = 808.6 m