A 15g bullet strikes and becomes embedded in a 1.10kg block of wood placed on a horizontal surface just in front of the gun. If the coefficient of kinetic friction between the block and the surface is .25, and the impact drives the block a distance of 9.5m before it comes to rest, what was the muzzle speed of the bullet?
The Attempt at a Solution
I know I will eventually use the above equation in order to solve for V1 but i don't quite understand had to use the other information given such as the friction in order to get to this point in the problem solving process. Any advice please?