Solving Fun Ski Area Problem: 3.67x10^7 W

[Vanessa23]

[SOLVED] Fun ski area problem

Homework Statement

A T-bar tow is planned in a new ski area. At anyone time, it will be required, to pull a maximum of 82 skiers up a 609-m slope inclined at 14.1° above the horizontal at a speed of 2.37 m/s. The coefficient of kinetic friction between the skiers skis and the snow is typically 0.0600. As the manager of the facility, what motor power should you request of the construction contractor if the mass of the average skier is 66.0 kg. Assume you want to be ready for any emergency and will order a motor whose power rating is 54.0 percent larger than the bare minimum.

Homework Equations

N = mg cosθ
and
F = mg (sinθ + μcosθ)
and
Po = Fv

so solve for P in: P = (Po + .54 Po)N

The Attempt at a Solution

P=((66.0*82*g)*(sinΘ + .06cosΘ))*2.37) +
(.54)*((66.0*82*g)*(sinΘ + .06cosΘ))*2.37)

I then multiply the answer for P times (66.0*g*cosΘ)
Answer=3.67x10^7 W

The program we submit our answers to says that my answer is wrong. I don't know what I am doing wrong. Thank you for any help!

 

[Doc Al]

The Attempt at a Solution

P=((66.0*82*g)*(sinΘ + .06cosΘ))*2.37) +
(.54)*((66.0*82*g)*(sinΘ + .06cosΘ))*2.37)

This seems reasonable.

I then multiply the answer for P times (66.0*g*cosΘ)

Why?? P is your answer.

 

[Vanessa23]

Our professor went over the problem in class and said we should multiply it by N and N is mg*cos(theta). He said that when we figure out N we should use the mass of only one skier.

 

[Doc Al]

Sorry, but that makes no sense to me at all. It won't even have the correct units.