Hi guys, we use bernoulli's equation for inviscid flows, like water and gas. But for gases, we also have the ideal gas law, let's say if i want to calculate energy within a gasous system, like a gas in a fixed space (e.g. a room; a tank etc...) Looking at ideal gas law, PV=mRT, PV will give me the energy. But if i use Bernoulli's equation, P/rho*g + v^2/2g +h, i can rearrange the equation to P + v^2*rho/2 + rho*g*h, and if i times volume into it, it becomes PV + v^2*rho*V/2 +rho*g*h*V which gives me energy. For a gas 'sitting' in a container (without gas moving in or out of the container), I can take away the kinetic energy part right? And the potential energy part will stay because of gas particles occupying a constant space, is this a correct assumption? The reason i am asking is because if the potential energy part also falls away, then the ideal gas law correspond to Bernoulli's equation (Even though i believe the potential energy term should stay). But if the potential energy do stay, then Bernoulli's equation will always have a higher energy value than the ideal gas law, which raise the question of when would you use ideal gas law and when would you use Bernoulli's equation to calculate energy in a gas system? Thanks!