Final Velocity of Hockey Puck: 40.0 m/s to ?

[Miike012]

Final Velocity...

Problem: A hockey puck is given an initial velocity of 40.0 m/s
along the ice. Find the speed of the puck 1.00 s later if
the coefficient of kinetic friction (U) between puck and ice is
0.600. (HINT: The result is independent of the mass of
the puck.)


My solution:

1. sum of forces in y direction = N - W = 0
2. sum of forces in x direction = p - f = (a)

p - (U)(N) = a
p - (0.600)(g) = a
p - 5.88 = a

( I need to know what "a" is in order to solve for final velocity but I am doing something wrong... please help)

PS. is my body diagram correct?

 

[QuarkCharmer]

The initial push vector you have is basically zero. It has an initial velocity, but no force acting on it in that direction. You can set up F-ma with that as zero, and you should be able to solve it for acceleration.

Take a look at this problem, it's very similar.
https://www.physicsforums.com/showthread.php?t=539748