# Homework Help: Energy Theorem

1. Feb 21, 2008

### soul5

1. The problem statement, all variables and given/known data
A water skier is moving at 14m/s. The rope makes a 35 degree angle with the centre line of the boat. If the tension in the rope is 90.0N, how much work does the resistive force of the water do on the skier while traveling 50 meters.

2. Relevant equations
W=FD

3. The attempt at a solution
I tried finding F in the x?

2. Feb 21, 2008

### Dick

I don't think you tried hard enough. Can you show us what you did? Since the skier is not accelerating the resistive force balances the x component of the tension force.

3. Feb 21, 2008

There is no acceleration so draw the force diagram. x-part of the tension is equal to the resistance.

4. Feb 21, 2008

### Dick

In what way does that differ from what I said? Or are you just reinforcing the point?

5. Feb 21, 2008

### soul5

lol what does that mean?

6. Feb 21, 2008

### Dick

You quoted equations, I thought you knew how to use them. W=F*D where F is the component of the force in the direction of the displacement. Compute the component of the tension in the direction of motion, lol.

7. Feb 23, 2008