Problems with Work and Kinetic Energy

[chippercheeta]

Hey, I have been fiddling with with problem all day today and I really have no idea how to even approach it. I was wondering if anyone could help shed some light onto it for me. Any help would be greatly appreciated!

[HRW7 7.P.042.] A skier pulled by a tow rope up a frictionless ski slope that makes an angle of 12° with the horizontal. The rope moves parrallel to the slope with a constant speed of 1.0 m/s. The force of the rope does 950 J of work on the skier as the skier moves a distance of 8.0 m up the incline.

(a) If the rope moved with a constant speed of 2.0 m/s, how much work would the force of the rope do on the skier as the skier moved a distance of 8.0 m up the incline?
___________J
(b) At what rate is the force of the rope doing work on the skier when the rope moves with a speed of 1.0 m/s?
__________W
(c) At what rate is the force of the rope doing work on the skier when the rope moves with a speed of 2.0 m/s?
________W


Thanks so much!

-Ashley

 

[Pyrrhus]

What have you done?

Do you know?

$$\sum_{i=1}^{n} W_{i} = \Delta K$$

 

[chippercheeta]

well I am not very good at physics (at all)

Im not familiar with that equation I don't think we covered that in our class.

I have no idea how to read the problem even to begin to answer it. It all makes no sense and the book my teacher uses is useless... I tried drawing out a diagram and I have tried the force=mgsin(theta) but I don't have the mass to find that and that's pretty much the only thing I know to try to do.

 

[Pyrrhus]

The problem is... this is a work-kinetic energy theorem problem.

Study this sites explanations.

http://hyperphysics.phy-astr.gsu.edu/hbase/work.html#wepr

http://online.cctt.org/physicslab/content/phyapb/lessonnotes/workenergy/lessonwork.asp