Thanks.

Many thanks

Fantastic, thank you again

Much appreciated, I'll work through this tonight. Many thanks.

Sorry, that must be a typo, we must assume closed system

So I can find the masses of each from the ideal gas law, and then using the isentropic relationships pV^gamma, and TV^(gamma-1), I can find Pressure & Temp after first compression stroke. But what about Q4), after the expansion stroke, finding the Pressure & Temp, I think I use isentropic relationships again, but not sure what the P1 and V1 are now, any help much appreciated. Thanks.

For Q1 finding the masses, - do I use pV = mRT in each case: e.g. the Cylinder Volume = 0.001508m^3, & Vb/Vc = 0.9, so Bottle Volume = 0.001357m^3 So is the mass of air in the Bottle m = pV/RT = 101325 x 0.001357 / 287 x 298 = 0.0016 kg Am I on the right track? Many thanks

Just saw this too, but I'm still struggling a little

Thanks for your help Frictionless

But in Part B, you said: 'The heat added at constant volume is divided into increasing the internal energy and doing the work against the piston(Atmosphere) to keep the pressure constant' But doing work against the piston (atmosphere) would suggest it isn't constant volume?

Brilliant, thank you

I'm glad of your support. Great forum. :)

Don't apologise, I just marvel at your knowledge. Many thanks again.

Thank you, I will. You just seem to pluck these formula's out of the air, I have never seen that formula below before, amazing. :)

Perfect, thank you very much.

Yes, I guess we have to make assumptions. Thanks

Yes, I agree, a piston in cylinder should be a closed system!! Your answer is very useful, thanks. Just wondering, do we need to find entropy values if we're only looking for h1 and h2?

Thanks again

Many thanks. Fantastic.

Ah hang on, PV= C, so C is a constant, so in that case W = P1V1 ln(V2/V1) Is that correct?