Question

1. A child starts sledding from rest, going down a 40 m long 7.5° incline, then coasting across a horizontal stretch. The mass of the sled + child is 35 kg, and the coefficient of kinetic friction is 0.060.

Answer 1

Answer

Energy loss due to friction is given by

$E=\mu mgS cos\theta$

$E=0.060\times 35\times 9.8\times \cos 7.5°$

$E=20.40J$