I'm having trouble solving this problem. can n e one help me?(adsbygoogle = window.adsbygoogle || []).push({});

A bungee jumper of mass 64.5 kg (including safety gear) is

standing on a platform 48.0 m above a river. The length of

the unstretched bungee cord is 10.1 m. The force constant

of the cord is 65.5 N/m. The jumper falls from rest and just

touches the water at a speed of zero. The cord acts like an

ideal spring. Use conservation of energy to determine the

jumperâ€™s speed at a height of 12.5 m above the water on

the first fall.

I used the work equation to find the total energy, then subtracted the elastic potential energy and gravitational potential energy at 12.5m above ground. Then i solved for Ek, and used THAT equation to solve for speed.

i got 9.29m/s, but the answer is 6.37m/s.

What did i do wrong?

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# Homework Help: Energy problem on bungee jumper

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