Work and Heat - Thermodynamics

[luv8724]

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Will there be a question regarding how heat is transferred to work on DAT?

like w = PV

and how that constant volume will do no work

 

[dentalWorks]

if memory serves... I think I had a GC question on my DAT that had me use the w = PV

 

[sfoksn]

if memory serves... I think i had a gc question on my dat that had me use the w = pv

w= -p*v 🙂

 

[luv8724]

w= -p*v 🙂

how is it that it's negaive pressure...

at least in DAT it's gonna be a constant pressure im assuming..

 

[Erhatstil]

ive always looked at it like this: if w=-p*v and *v=(v2-v1) then positive work must be done if we're going from a large space (v1) to a small space (v2) like with a car piston.

if a piston compresses a cylinder, then the pressure inside must be increasing. so the p from the equation w=-p*v, which represents external pressure, would most likely be decreasing, and thus, is negative.

not sure if this is the correct way of looking at it, but its the way i do. hope it helps.

 

[luv8724]

ive always looked at it like this: if w=-p*v and *v=(v2-v1) then positive work must be done if we're going from a large space (v1) to a small space (v2) like with a car piston.

if a piston compresses a cylinder, then the pressure inside must be increasing. so the p from the equation w=-p*v, which represents external pressure, would most likely be decreasing, and thus, is negative.

not sure if this is the correct way of looking at it, but its the way i do. hope it helps.

What I thought it as was that the piston experiment seems to explain how

heat can be changed completely to work. oh psh...

can someone explain