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newRPL: Handling of units
05-08-2016, 09:06 PM (This post was last modified: 05-08-2016 10:09 PM by emece67.)
Post: #12
RE: newRPL: Handling of units
Hi all,

In a case like: what's the final temperature of 2 kg of liquid water at 20ºC that is heated if the total amount of heat transferred to it is 25000 J?

From \(Q = mC\Delta T\) you will get \(\Delta T = {Q\over mC}\), with \(C=4182 {J\over kg \Delta K}\) being the specific heat of water at 20ºC. With this you get \[\Delta T = {25000 J\over 2kg · 4182 {J\over kg \Delta K}} = 2.989 \Delta K\]

Then the final temperature will be: \(T_0+\Delta T = 20 ºC + 2.989 \Delta K =\) Inconsistent units.

I don't see the point on \(T\) and \(\Delta T\) units being inconsistent in addition and subtraction.

EDIT: and for the \({T\over\Delta T}\) and \({\Delta T\over T}\) cases. Will: convert \(T\) to the absolute scale associated with \(\Delta T\); discard units; perform division, solve the \({K\over\Delta K}\) glitch? This way 10ºF / 1ΔK = 469.67ºR / 1ΔºC = -12.22ºC / 1ΔK = 260.928 K / 1ΔºC = 260.928.
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Messages In This Thread
newRPL: Handling of units - Claudio L. - 09-23-2015, 03:38 PM
RE: newRPL: Handling of units - Han - 09-27-2015, 02:29 PM
RE: newRPL: Handling of units - Claudio L. - 09-28-2015, 01:50 PM
RE: newRPL: Handling of units - Claudio L. - 09-30-2015, 06:02 PM
RE: newRPL: Handling of units - JoJo1973 - 05-08-2016, 01:30 PM
RE: newRPL: Handling of units - JoJo1973 - 05-08-2016, 04:28 PM
RE: newRPL: Handling of units - Claudio L. - 05-08-2016, 05:38 PM
RE: newRPL: Handling of units - Claudio L. - 05-09-2016, 05:42 PM
RE: newRPL: Handling of units - JoJo1973 - 05-09-2016, 06:05 PM
RE: newRPL: Handling of units - Vtile - 05-11-2016, 02:27 PM
RE: newRPL: Handling of units - JoJo1973 - 05-08-2016, 06:21 PM
RE: newRPL: Handling of units - Claudio L. - 05-08-2016, 06:24 PM
RE: newRPL: Handling of units - JoJo1973 - 05-08-2016, 10:44 PM
RE: newRPL: Handling of units - emece67 - 05-08-2016 09:06 PM
RE: newRPL: Handling of units - Claudio L. - 05-09-2016, 12:41 AM
RE: newRPL: Handling of units - emece67 - 05-08-2016, 10:01 PM
RE: newRPL: Handling of units - Claudio L. - 05-09-2016, 12:59 AM
RE: newRPL: Handling of units - emece67 - 05-09-2016, 05:55 AM
RE: newRPL: Handling of units - JoJo1973 - 05-09-2016, 09:22 AM
RE: newRPL: Handling of units - Claudio L. - 05-09-2016, 01:46 PM
RE: newRPL: Handling of units - JoJo1973 - 05-09-2016, 09:27 PM
RE: newRPL: Handling of units - Claudio L. - 05-11-2016, 02:49 AM
RE: newRPL: Handling of units - JoJo1973 - 05-12-2016, 11:18 AM
RE: newRPL: Handling of units - Claudio L. - 05-09-2016, 09:51 AM
RE: newRPL: Handling of units - Claudio L. - 05-11-2016, 05:01 PM
RE: newRPL: Handling of units - Helix - 05-12-2016, 01:07 PM
RE: newRPL: Handling of units - Claudio L. - 05-12-2016, 04:58 PM
RE: newRPL: Handling of units - Helix - 05-12-2016, 11:58 PM
RE: newRPL: Handling of units - Claudio L. - 05-13-2016, 01:43 AM
RE: newRPL: Handling of units - Claudio L. - 05-13-2016, 01:35 PM
RE: newRPL: Handling of units - Helix - 05-13-2016, 11:12 PM
RE: newRPL: Handling of units - Claudio L. - 05-14-2016, 02:57 AM



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