A block of mass 2kg, moving at velocity 2.68 m/s, slides across a rough 3m surface with a coefficient of kinetic friction of .4. Calculate the energy lost to the 3m rough surface.
2. Relevant equations
3. The attempt at a solution
I used the kinetic energy equation of 1/2mv^2 to get 7.18J. Then I did uK*Fn*D to get 24J, where Fn is normal force and Gravity = 10m/s^2. I have no idea where to go from here.