Homework Help: Bungee jump

1. Feb 28, 2008

gillyr2

1. The problem statement, all variables and given/known data

Chris jumps off a bridge with a bungee cord tied around his ankle. He falls for 15m before the bungee cord begins to stretch. Chris's mass is 75kg and we assume the cord obeys Hooke's law F = -kx, with k=50N/m. If we neglect air resistance estimate how far below the bridge Chris's foor will be before coming to a stop. Ignore the mass of the cord and treat Chris as a particle.

2. Relevant equations
well i know h = 60m. but i don't know how im suppose to get there.

3. The attempt at a solution

no idea what so ever

2. Feb 29, 2008

gillyr2

pleae someone help

3. Feb 29, 2008

Staff: Mentor

Use conservation of energy.

4. Mar 3, 2008

gillyr2

how exactly do i encorporate hookes law in the conservation of energy equation?

5. Mar 4, 2008

Staff: Mentor

What's the expression for the elastic potential energy stored in a stretched spring?

6. Mar 4, 2008

tiny-tim

"Relevant equations"

Hi gilly!

Whoa! Don't do it all at once. Don't start incorporating one thing into another.

You have two objects - Chris and the cord.

What is the energy of each?

Write them down separately. Then go from there.