## Hockey Puck problem

1. The problem statement, all variables and given/known data
A hockey puck with a mass of 0.50 kg is hit in a straight line along a horizontal playing surface.
Well, there are 4 parts to this question:
a. If the puck has an initial velocity of 4.0m/s and stops after 5.0, what is the coefficient of friction, uk1, of the playing surface?
My answer: for this one, I got 0.16 and I'm quite sure it's right, unless someone can prove me wrong.

b. What should the initial velocity be if the coefficient of friction is 0.16 and the puck has to travel 6.0m?
My answer: I got 4.4m/s and again I think it's right, unless someone can prove me wrong.

c. Someone spills food on the playing surface, changing the coefficient of friction over a 1.0 m section. Now, in order for the puck to travel 6.0 m, it first goes 4.0 m over a surface with a coefficient of friction of 0.16, then it goes 1.0m over a surface with a coefficient of friction uk2, and finally it goes 1.0 m over a surface with a coefficient of friction of 0.16 again. If the initial velocity of the puck in a straight line must now be 5.0 m/s in order to travel 5.0m, what is the coefficient of friction, uk2?