You are a member of an alpine rescue team and must project a box of supplies, with mass m, up an incline of constant slope angle α so that it reaches a stranded skier who is a vertical distance h above the bottom of the incline. The incline is slippery, but there is some friction present, with kinetic friction coefficient μk. Use the work–energy theorem to calculate the minimum speed you must give the box at the bottom of the incline so that it will reach the skier.