I'm getting stuck on where this additional energy comes to move the piston further outward/inward during adiabatic processes when the only energy changed is during isothermal processes. Can someone care to explain?
They come from work, i.e. expansion or compression of the gas.
This question is a duplication. It's already been asked here:
The most common adiabatic cycle is the internal combustion engine. The energy for this process obviously comes from the combustion of gasoline in each cylinder of the engine. The process can be considered adiabatic because a typical car engine will be operating in the range of 2000-3000 rpm under normal driving conditions, and at these speeds, there is VERY little time for heat transfer to cooling water or the environment during a the four stroke engine cycle.