1. The problem statement, all variables and given/known data Physics and Skiers and Rope and Hills? A 80 kg skier grips a moving rope that is powered by an engine and is pulled at constant speed to the top of a 24 degrees hill. The skier is pulled a distance x= 200m along the incline and it takes 2.2 min to reach the top of the hill. If the coefficient of kinetic friction between the snow and skis is Uk = 0.12, what horsepower engine is required if 30 such skiers (max) are on the rope at one time? 2. Relevant equations F=umgcos(theta) P=F(change in x)/t HP=746? 3. The attempt at a solution Since the tow rope moves at constant speed, the tension in the rope must equal the force of kinetic friction, which is: f = μmgcosθ = 0.12(80kg)(9.8m/s²)cos24° = 86N (rounded) Power is work over time and work is force times distance, so: P = FΔx / t = 86N(200m) / 132s = 130 W In horsepower: 130W = 130W(1.00HP / 746W) = 0.175HP For 30 skiers then: 30 x 0.175HP = 5.3HP (rounded) I got the wrong answer when I put this in. Everything seems in order. Did I miss something? I've double checked my work so its not a calculator error. Any help=thanks!