# Developing equation for rare gas thermometer using F

1. Aug 26, 2009

### drewmacq

1. The problem statement, all variables and given/known data
Develop an analogous equation for a rare gas thermometer using the Fahrenheit scale as reference points.

2. Relevant equations

T = aL + b where L is length of metal rod used to determine scale, a and b are constants

expansion coefficient = 2.7315

3. The attempt at a solution

So we derived the formula for Kelvin scale in class using T = aL + b, and now we're supposed to do the same with Fahrenheit. I've been working for a little over a week now and have come up with little to nothing. I don't need answers, I need somewhere to start

I tried using 32, the freezing point in the F scale, in that first equation to get

32 = aL + b

When we used Celsius to get the Kelvin scale, this worked well because freezing point was zero and that meant b = -aL ... from there I could figure the rest of the derivation out..

I tried to use 212 as the boiling point to get:

212 = aL + b

I then substituted b from the second equation into the first, took up a few pieces of paper with math, and came out with a bunch of hot mess.... any suggestions???