Question

A hockey puck is hit on a frozen lake and starts moving with a speed of 14.4 m/s. 3.0 seconds later, its speed is 7.3 m/s.
(b) What is the average value of the coefficient of kinetic friction between puck and ice?

Answer 1

First, find the acceleration:

7.3 = 14.4 - a*t

Substitute 3 seconds into the above equation to find the acceleration a. This acceleration is due to the force of friction = ckf*m*g

where ckf is the coefficient of kinetic friction, m is the mass of the puck, and g is the acceleration due to gravity

m*a = ckf*m*g

ckf = a/g