/sci/ - Science & Math

[Anonymous No.4224773]

I understand that increasing the temperature of a closed system will increase the pressure within the system however, is the converse true?

Can increasing the pressure of a system cause the temperature to also increase? If so, how? I imagine you would have to do this by keeping the volume constant but how would you increase the pressure whilst keeping the volume constant and not increasing the temperature?

All I can think of is adding more mass but then it's not really a closed system.

So /sci/, if increasing the pressure without altering the volume or directly altering the temperature of a closed system is even possible, would this lead to an increase in temperature?

[Anonymous No.4224778]

Bump.

[Anonymous No.4224792]

Bump

[Anonymous No.4224793]

http://en.wikipedia.org/wiki/Ideal_gas_law

[Anonymous No.4224796]

if you imagine that system as sphere full of some gas X then pV = nRt , R is constant, to increase pressure you need to do any or any combination of:
a) decreasing volume
b) increasing number of molecules/atoms
c) increase temperature

[Anonymous No.4224799]

>Can increasing the pressure of a system cause the temperature to also increase?

Yes but it's inefficient compared to using radiative heating AFAIK. It works in reverse as well. That's how refrigerators work.

[Anonymous No.4224800]

Well you have the equation of state, for example

PV=nRT

en.wikipedia.org/wiki/Equation_of_state#Classical_ideal_gas_law

or more generally, depending on your system, this

http://en.wikipedia.org/wiki/Grand_canonical_ensemble#Thermodynamic_quantities
(third line)

or this

http://en.wikipedia.org/wiki/Benedict%E2%80%93Webb%E2%80%93Rubin_equation

if you're an asshole engineer and into numerics.

Lets stick with
PV=nRT
or
PV=NkT

If V and N really are constant, then P=cT and increasing pressure is the same thing as heating it.

In any case, the abstract definition of P is that it's
-dU(S,V)/dV, i.e. if you want to change P you have to get to another energy value, i.e. change the value of the entropy somehow. If you can't get inside the box you need diffusion or radiation or whatnot.

[Anonymous No.4224893]

where do those hands holding glasses picture come from.

[GL !Bgpe2HycPk No.4224903]

>>4224893
>those hands holding glasses picture