Problem 2 (A Force + Motion Problem)

4.7 of text:

A 68.5 kg skater moving initially at 2.40 m/s on rough horizontal ice comes to rest uniformly

(with constant acceleration) in 3.52 s due to friction from the ice. What force does friction exert

on the skater?

Hint: First, model the skater as slowing down with a constant acceleration. Second, given the

stopping time find what that acceleration is. Then, use that acceleration to find the net force

from Newton's second law.