Calculating Work: Solving a Skiing Problem on a 30 Degree Slope

[ashkitten21]

A skier of mass 64 kg is pulled up a slope by a motor-driven cable. How much work is required to pull him 80 meters up a 30 degree slope (assumed frictionless) at a constant speed of 3.1 meters/second? [answer is to be in joules]


Ok, so the equation I am using is W = (Fcos(theta))*delta x

I tried using the values above and I've done it over and over and still came up with the same number.

W = ((3.1*64)*cos30)*80

= 13745.6

Am I missing something obvious? Thanks in advance for any helpful suggestions.

 

[Päällikkö]

If there was no slope, a force of what magnitude would be required to keep up a constant speed?
And as dW = F dx, how much work would be required for the 80m trip?

Hope this helps you figure out what you did wrong :).

 

[ashkitten21]

Ok, I got it . . .Thank you.