# Youngs modulus

1. Nov 5, 2006

### mikefitz

A wire of length 4.95 m with a cross-sectional area of 0.103 cm^2 stretches by 6.55 mm when a load of 0.94 kN is hung from it. What is the Young's modulus for this wire?

FA = Y (delta L/L)

0.103 (cm^2) = 1.03 × 10-5 m^2
6.55 millimeters = 0.00655 meters

= 9221.4 N x 1.03 × 10-5 m^2 = .09498

0.00655m / 4.95m = 0.00132323232
.09498 / 0.00132323232 = 71.7787788 Pa ????

what did i do wrong?

2. Nov 5, 2006

$$\Delta l = \frac{Fl}{YA} \Rightarrow Y = \frac{Fl}{\Delta l A}$$.

3. Nov 5, 2006

### mikefitz

Y = 940N * 4.95m
------------
.00655m * 1.03(10^-5)m^2

Y = 6.90356083 × 10^10

Does this seem correct? thanks for the help

4. Nov 5, 2006