00:01
For this problem, we will first assume that the process is quasi -equilibrium.
00:06
Now, the pressure of the gas changes linearly with volume, as we can see in our diagram.
00:10
And thus, the process curve on a pv diagram is a straight line.
00:14
The boundary work during this process is simply the area under the process curve, which is trapezoidal.
00:23
So we need to find the trapezoid area under the curve.
00:27
So the first thing we will do is find p1.
00:32
P1 is equal to a, v1, plus b.
00:37
And this is equal to minus 1 ,200 kilopascals per cubic meter times v1, which is 0 .42 cubic meters, plus b, which is 600 kilopascals.
01:07
So we get p1 to be 96 kilopascals.
01:15
And p2 is equal to a v2 plus b so the pressure of state 2 is equal to minus 1 ,200 kilopascals a cubic meter times the final volume 0 .12 cubic meters plus 600 kilo -pascals.
01:47
Hence we get the final pressure of the system to be 456 kilopascals.
01:57
And now we can calculate the boundary walk.
02:01
So the boundary walk, wb, is the area under our trapezoid...