ap physics
posted by shanster on .
A skier of mass 70.5 kg is pulled up a slope by a motordriven cable. How much work is required to pull the skier 60 m up a 38° slope (assumed to be frictionless) at a constant speed of 2.0 m/s?

The elevation gain is
H = 60 sin38 = 36.9 m
The energy required is the potential energy gain,
E = M g H
The speed does not matter, as long as it is constant. Kinetic energy stays the same. 
25521 J

work=20,580J
power=686 watts 
18081 J

A skier of mass 61.0 kg is pulled up a slope by a motordriven cable. (a) How much work is required to pull him 40.0 m up a 30.0° slope (assumed frictionless) at a constant speed of 4.00 m/s? (b) What power must a motor have to perform this task?

skier of mass 79 kg is pulled up a slope by a motordriven cable.
(a) How much work is required to pull him 80 m up a 30° slope (assumed frictionless) at a constant speed of 3.4 m/s?
1 J
(b) What power (expressed in hp) must a motor have to perform this task?