Question

1. A hockey puck of mass 0.245 kg leaves a hockey stick at a speed of 29 m/s.  The coefficient of kinetic friction between the ice and puck is 0.080.

a. What is the acceleration of the puck once it leaves the stick?

b. How long will it take for the puck to stop?

c. Repeat part (a) for a puck of twice the mass.

Answer 1

a) The acceleration can be found from Newton's second law:

$$ma=\mu mg,\\ a=\mu g=0.784\text{ m/s}^2.$$

b) The time is

$$t=v/a=37\text{ s}.$$

c) The acceleration will be the same.