You are a member of an alpine rescue team and must get a box of supplies, with mass 2.20 kg, up an incline of constant slope angle 30.0 degrees so that it reaches a stranded skier who is a vertical distance 2.80 m above the bottom of the incline. There is some friction present; the kinetic coefficient of friction is 6.00×10^−2. Since you can't walk up the incline, you give the box a push that gives it an initial velocity; then the box slides up the incline, slowing down under the forces of friction and gravity. Take acceleration due to gravity to be 9.81 m/s^2.
Use the work-energy theorem to calculate the minimum speed v that you must give the box at the bottom of the incline so that it will reach the skier.
W= kf-ki+ uf-ui
The Attempt at a Solution
I don't really see how the work-energy theorem applies. I know we have the kinetic coefficient of friction, but what about the potential. I'm very confused by this problem!