00:01
So we're looking to find the force that we need to enact on piston b in order to balance this system, so that neither of the pistons in these two chambers move, which are connected together by a tube.
00:15
So we have some pressure p in both of these chambers, and in order to ensure that they're not moving, we want to make sure that the pressures are equal across these two chambers, because if there's no pressure difference across the two chambers, then no gas will flow in between them, keeping the system at rest.
00:40
So what we're first going to do is we're going to set up an equation that describes the forces at rest that are enacting on the pistons.
00:49
So for chamber a, we have the pressure due to the gas that's pushing up.
00:57
We have this force f .a.
01:00
And also the force due to atmospheric pressure.
01:07
And for chamber b, we have a pretty similar equation.
01:12
We have the pressure pushing up on piston b as a result of the pressure in the chamber, and we're looking to find what force we need to push down on it in addition to the atmospheric pressure.
01:30
So what we're going to do here is we know that p has to be equal, the pressure inside the chamber, so when we rearrange, what we'll have, when we set the expressions equal to each other once we solve for p, is we'll have an expression that looks like this...