00:01
So what we're going to do here is we're going to find what mass we need for this piston to ensure that there's a pressure of 1 ,500 kilopascals.
00:13
And we're given that there is an atmospheric pressure of one bar, which is equal to 1 kilopascal.
00:18
So how are we going to go about finding the mass? so what we can do is we can write an equation that balances the forces on the piston when this piston is at rest.
00:30
So if we look at this diagram, we have some liquid within that the piston is pressing down on.
00:37
So there's some pressure going up, an upwards force applied on the piston.
00:45
And counteracting that is the force of gravity.
00:49
So i'll just write fg.
00:50
And we also have the force of atmospheric pressure, which i'll write is p .o.
00:56
Times a.
00:59
So if we go ahead and write down the equation that would balance these forces, we'll have pressure coming from underneath the piston times the area, which is equal the force coming up...