A 59-kg water skier is being pulled by a nylon tow rope that is attached to a boat. The unstretched length of

the rope is 12 m and its cross-sectional area is 2.0 x 10^-4 m^2. As the skier moves, a resistive force (due to the water) of magnitude 130 N acts on her; this force is directed opposite to her motion. What is the change in the length of the rope when the skier has an acceleration whose magnitude is 0.85 m/s?


Any physicists in the house?

Assuming the acceleration and the water resistive forces to be in the line of the rope then:

Force on skier = 130 + 0.85 x 59 = 180. N

Extension of rope = E x 180 x 12 x 10000/2 = E x 1080 x 10000 m.

where E is the Young's modulus of nylon, which I leave you the pleasure of finding.

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