Doug hits hockey puck giving it an initial velocity of 6.0 m/s. If the coefficient of kinetic friction between ice and puck is 0.050, how far will the puck slide before stopping?

Use the concept of the puck's initial kinetic energy:

KE = 1/2m v^2

equals the work done as the puck slides alomg:

W = Fd,

where F is the friction force:

F = \mumg

Solve for d.

Or if you prefer using kinematics,

The force of friction is:

F = \mu mg

This gives a deceleration '-a', given by:

F = -ma

Thus you get:

\mu mg = -ma

\mu g = -a

Then use

v^2 = u^2 + 2as

Where v = 0 m/s
u = 6 m/s
a = -0.05g m/s^2
s = ? M