# Tension in a wire, length change

## Homework Statement

3. A flying chicken (m = 450[gram]) lands in the middle of a taught laundry wire of length l=10[m]. The wire has a negligible mass. The chicken causes the wire to stretch by 0.05% from its original length. Find the tension in each segment of the wire.

http://img517.imageshack.us/img517/2922/asdfgggea7.th.jpg [Broken]http://g.imageshack.us/thpix.php [Broken]

## Homework Equations

Fext = 0

X) Ft1x - Ft2x = 0

Y) Ft1y + Ft2y - Fg = 0

## The Attempt at a Solution

Since the length increases by .05% you can make a triangle with lengths 10m ( the origianl length), 5.25m and 5.25m (half of the new length with the chicken in the middle). you can split this into two right triangles with sides 5-5.25-x (doesn't matter right?). Using arccos (5/5.25) you get 17.8 degrees.

Fty1 & Fty2 = Ftx tan 17.8

getting 2 Ftx tan 17.8 = Fg

Ftx = 6.87 N

Ft = Ftx/Cos 17.8 = 7.2 N

The Problem

Students in my class got 69.8 N, and after looking up tension I found that it increases as things stretch. Our teacher never said anything about this (but gave a problem on it). How does the streching of the string play into this? Is there some equation I'm not putting to use?

Last edited by a moderator: