I don't understand the "Note there is not pressure term" phrase. Pressure has to be a component as pressure is from the force of the expanding gas on a finite area at a static point in time(otherwise time varying because the volume is increasing)and is what starts it all. It's in there somewhere and I would say the effect of the bounding/excited molecules(kg) with a velocity(m/s^w)acting upon the finite area(m^2)of the base of the wad would give a force(N=kg m/s^2) but I don't have my units correct just yet.

Kind Regards,

Raimey

rse

Last edited by ellenbr; 09/03/08 10:44 PM.