area and elasticity

[chiddler]

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Young's modulus, Y = F(delta L)/AL

Common knowledge is that increasing cross sectional area of a solid will make it less elastic. How does this equation reflect this?

Delta L and A are proportional. So increasing area would increase delta L.

thank you.

 

[ljc]

Young's modulus, Y = F(delta L)/AL

Common knowledge is that increasing cross sectional area of a solid will make it less elastic. How does this equation reflect this?

Delta L and A are proportional. So increasing area would increase delta L.

thank you.

I'm INCREDIBLY tired so I might be making a mistake here, but i think you have the equation wrong.

It should be Y=FL/(A*deltaL)
So now, increasing area decreases the change in length, which is what we'd expect.

 

[SaintJude]

Yeah, ljc. has the equation right. After rearrangement Y = FL/ (A ΔL ) . Stiffer materials will have higher Young modulus.

Careful though: Young's modulus for any material is a constant. So you can't increase an object's intrinsic Young modulus value by increasing it's cross-sectional area.

 

[chiddler]

oh...

that explains a lot xD

thank you.