# Why are temperature/voltage/etc not measured all in KJ?

why are temperature/voltage/etc not measured all in KJ???

ditto.....

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dextercioby
Homework Helper
Why???They're all other physical quantities.

Daniel.

Pengwuino
Gold Member
dextercioby said:
Why???They're all other physical quantities.

Daniel.
Yah what he said :P

Joules is a unit of work/heat. Temperature is a state variable. Voltage is another state variable. Its like asking why isnt mass measured in Joules.

dextercioby
Homework Helper
It's not necessarily thermodynamics.Voltage for example is not defined in thermodynamics.

Daniel.

pervect
Staff Emeritus
Voltage is already measured in joules/columb - energy / unit charge.

Temperature scales were around long before thermodynamics, so they are a bit of a legacy unit. And they are conveniently sized for everyday use.

i mean, why aren't the energies measured in the same unit? also, chemical energy is measured in jouldes, in food atleast...

and i din't relise that joules were used for electricity

PS: im only doing a single physics for my science GCSE, but next year i should hopefully be doing AS physics

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dextercioby
Homework Helper
Energies are measured in various units.It's either erg,or Joule,or Calorie and many more.Between them there are the so-called CONVERSION RULES.Just like in the scales for temperature...

Daniel.

We are unfortunate for having so many systems of measurement. This is not the case only with energy. Consider length, or mass. We have metres, miles, feet, inches, kg, ounces, pounds, and so on.
But just take the SI system as the official one, and you will have one basic unit for each quantity.

brewnog