A skier of mass 70 kg is pulled up a slope by a motor-driven cable. (a) How much work is required to pull him 60m up a 30 degree slope (assumed frictionless) at a constant speed of 2.0 m/s? (b) What power must a motor have to perform this task?

Answer 1

he changes height by 60 sin30

work= mgh
power= mgh/T= mg d*sin30/T= mgv/2

Answer 2

I keep getting a number that is very large for (a). Is mg 70kg * 9.81?

Answer 3

Yes, the expression of Joules is generally very large when dealing with human beings moving slow, or small projectiles moving fast.