# Homework Help: Bungee Cord Lab

1. Apr 12, 2004

### g4wonhyo

Hi, I am taking a physics class with one instructor and the physics lab with another instructor--it wasn't supposed to be that way, and my lab teacher is always giving me a hard time because of it ( I think he hates me.).

Anyway, I need some help with a take-home lab assignment that my lab instructor gave to me. In class, one end of a bungee cord was tied to the railing of the third floor and the other end was tied to a stuffed bear (.176 kg). The bear was dropped from the third floor so that it just barely touched the bottom of the first floor (10.0m). The length of the un-stretched cord was 4.00m, and the length of the stretched cord was 6.00m. I have to determine the maximum velocity and the spring constant. I'm not exactly sure which one I have to calculate first--I think I need the spring constant before I can calculate the maximum velocity (Am I right about that?). To determine the spring constant (k), can I divide the weight of the bear by the displacement of the cord from its un-stretched length?

k=W/x
=.176 kg (9.80 m/s^2)/(6.00m-4.00m)
=.862 N/m

Is that right? Thanks for your help.