# Homework Help: Young's Modulus (tensile Test)

1. May 4, 2012

### Joe123

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

Original Cross sectional area 24.63mm^2

original diameter 5.6mm

Gauge length 35.07mm

Extension length of the point on the graph i have chosen: 0.25mm

Force at 0.25mm extension 3500N (or 3.5KN)

2. Relevant equations

(F/A0)/(ΔL/L)

3. The attempt at a solution

I have gone through numerous attempts trying to solve this equation, i believe i am a factor of 10 out, as using the above equation gives me 19.9 GPa but i can't for the life of me figure out where i am missing the extra digit.

The materials are black mild steel and bright steel.

I've uploaded the graph in case i've stated anything wrong, looking at the first 3 specimens. (second graph is irrelevant)

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2. May 4, 2012

### PhanthomJay

Hi Joe welcome to PF!

Looks like yes, you are off by a factor of 10, so either your gauge length should be 350 mm or the extension is .025 mm. Perhaps the problem is mistyped.