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.

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