Energy Problem (Systems and Energy Conversion)

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Homework Statement

At what height should a parachute be opened so the final speed is 5.00 m/s. (The parachuter is 80.0 kg. He jumps off a balloon at 1,000 m. The total retarding force on the man is constant at 50.0 N with the parachute closed and constant at 3,600 N with the parachute open.)

Homework Equations

Kinetic Energy --- KE=1/2mv²
Potential Energy --- PE=mgy ... g=9.8 m/s²
Work --- W=Fd

The Attempt at a Solution

 

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