Calculations using Temperatures

[Heavenly]

I am trying to do a simple calculation using a coefficient of thermal expansion. But the result is not as expected. The units of thermal expansion coefficient are in/in/deg F.

I attached a sample spreadsheet in Mathcad 15. The answer should be 0.936in but I cant seem to get that. What am I doing wrong.

[ValeryOchkov · Accepted solution]

See te attach!

[wayne]

David,

for the temperature change, delta T, you need to use the unit "delt degree F", as you did for alpha: degree F by it iself relates to absolute 0 in Kelevin or 256K

[Heavenly]

Thanks that worked.

[ValeryOchkov]

See more correct alpha units in attach!

[ValeryOchkov]

Wayne Reid wrote:

David,

for the temperature change, delta T, you need to use the unit "delt degree F", as you did for alpha: degree F by it iself relates to absolute 0 in Kelevin or 256K

Sorry, but "delt degree F" is one stupid units (in Mathcad). We must use not "delt degree F" but R (rankine) or K (kelvin). Same with "delt degree C".

[wayne]

Valery,

Thanks, but the guy is just dealing with thermal expansion, and the unit works a intended. I have no doubt you are correct, but in the structural industry, in the US, alpha is normally in C or F and we generally only need the expected maximum change in temperature; Strictly correct or not, "delta degree F" for this application is fine.

Anyway, your fast.

Wayne

[ValeryOchkov]

Wayne Reid wrote:

Valery,

Thanks, but the guy is just dealing with thermal expansion, and the unit works a intended. I have no doubt you are correct, but in the structural industry, in the US, alpha is normally in C or F and we generally only need the expected maximum change in temperature; Strictly correct or not, "delta degree F" for this application is fine.

Anyway, your fast.

Wayne

Thanks Wayne, I know it!

>but in the structural industry, in the US, alpha is normally in C or F

See above the Mathcad-sheet with an error