Question

You are designing a ski lift to be pulled up the side of a mountain, dragged along on the snow by a towing line connected to a motor. The mountain makes an angle of 30° with the horizontal and the coefficient of kinetic friction between the ski lift and the snow is \mu_kμ k = 0.2. The chair with people will have a mass of 100 kg and has an initial speed of 2.0 meters/sec. After being dragged 10 meters up the side of the mountain it has a speed of 4 meters/sec. You are trying to decide between two motors, one that can provide a towing force of 1000 Newtons, and the other capable of pulling with a force of 500 Newtons (which costs half as much as the more powerful motor).

(a) Draw a Free Body diagram of the ski lift, showing all forces acting on the lift. (b) Which motor should you purchase so that you will be able to pull the ski lift under the conditions described above, at the lowest cost?

Answer 1

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