Water skiers often ride to one side of the center line of a boat, as shown in

Question:

Water skiers often ride to one side of the center line of a boat, as shown in FIGURE 7-20. In this case, the ski boat is traveling at 12 m/s and the tension in the rope is 91 N. If the boat does 3800 J of work on the skier in 50.0 m, what is the angle u between the tow rope and the center line of the boat?
In figure 7-20