posted by Elizabeth on .
A water skier, moving at a speed of 8.36 m/s, is being pulled by a tow rope that makes an angle of 33.4 ° with respect to the velocity of the boat (see the drawing). The tow rope is parallel to the water. The skier is moving in the same direction as the boat. If the tension in the tow rope is 140 N, determine the work that it does in 11.0 s.
I got 14400 J, which was incorrect.
The force component along the direction of motion is what does work. That component is 140 cos33.4 = 116.9 N
Distance travelled in 11.0 s = 91.96 m
Multiply those numbers together for the work done, in joules.
I have no idea how you got 1440 J. If you had mistakenly omitted the cosine term, you still should not get that answer.
Thank you! I redid it with different numbers, and I got the problem correct. :)