(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I am working on this ahead of my fall class and don't actually want the answer...

just pointers to help me understand something.. Thanks guys! :)

I am really rusty with my general physics and calculus knowledge =(

The original question asks me to prove that, for a solid, the linear thermal expansion coefficients (in x, y, z directions) add together to give the thermal expansion coefficient as such:

B=a_{x}+a_{y}+a_{z}

where B is the thermal expansion coefficient

B=(deltaV/V)/deltaT

deltaV= change in volume

V=volume

deltaT=change in temperature in Kelvin

and a is the linear thermal expansion coefficient

a=(deltaL/L)/deltaT

deltaL= change in length

deltaL=length

So here are my questions:

Shouldn't the equation be B=a_{x}*a_{y}*a_{z}instead? for a solid like a cube you have to multiply the lengths to get the volume... Why isn't it the same here?

Also is there a way to get the volume from the lengths of an object with calculus? I don't remember =( Just remember you can get the area under a curve from doing the integral or the volume of an object made by a curve somehow too...

2. Relevant equations

B=a_{x}+a_{y}+a_{z}

where B is the thermal expansion coefficient

B=(deltaV/V)/deltaT

deltaV= change in volume

V=volume

deltaT=change in temperature in Kelvin

and a is the linear thermal expansion coefficient

a=(deltaL/L)/deltaT

deltaL= change in length

deltaL=length

3. The attempt at a solution

uh.. well my attempt so far has been to understand the question. I tried to define the Volume as Lx+Ly+Lz but then got stuck. Please don't give me the answer though!! I got 3 months to work this out :)

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# Homework Help: Thermal Physics question regarding the thermal expansion coefficients

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