00:01
Okay, this question basically look at the heat engine, right? this heat engine, let me try to draw the sacchar.
00:12
The heat engine operates the pressure in kilo -pacar and the volume in centimeter cubic.
00:23
So let me try to draw a few of these values.
00:27
And this is 300.
00:29
And there's another one, which is 900.
00:31
And this is like this and goes from here is 200 and goes to about 600 and going up like this and this is 3 1 2 now this is this is the circle right so this is the circle i guess so this is as a sermon right so this is as a certain right constant temperature constant temperature, right? t is constant, constant temperature.
01:17
That occur up, right? and this is idea gas.
01:19
So let's, so basically you ask to work out the efficiency of this cycle, right? and first it's very clear that you can easily work out the walk down during this process, right? the walk down by this heat engine during this process, you can work it out.
01:37
So it's basically the area, right? and let's work out the area.
01:42
The area can be really nice.
01:44
So the work down has two parts.
01:47
First, you have this doing positive work and then doing the negative work, right? the positive work is given, of course, by the pressure, p times dv integration from v3 to v1, right? then this is given by, you know, v1, v3.
02:08
The word's p, p, of course, according to the gas equation, you know, pv equals nrt, right? and so p can be written as nrt over v.
02:21
And so this gives us nrt log v1 over v3.
02:28
So that is the work done, the positive work done, the positive work.
02:33
So i read it a plus, the positive work.
02:36
And the negative work, when the gas contracts, and that, of course, given by, you know, the area which is simply, because this is constant brazier, so it's simple.
02:45
It's just p times the volume change.
02:47
That is actually from v1 to v2, right? p1, p1, okay, times we 1 minus 2.
02:56
Okay, so that's the work.
02:57
So the total work, of course, is w plus minus w minus.
03:01
Okay.
03:01
So, and then we have to find the heat it absorbs, right, during the process.
03:06
And obviously, three and one has exactly the same temperature because i'm a summer process.
03:14
And it expands, it's due work.
03:16
And then i contract during this process.
03:21
So from one to two, from one to two is a constant pressure process.
03:26
And the volume is, the volume is obviously decreasing.
03:32
So temperature is higher.
03:33
So i would say this process.
03:36
And then, so temperature t2, so temperature t1 is less than in temperature t2, right? obviously because, but t1 and t3 are the same and t2 has a high temperature, right? so to know which process is absorbing heat? well, we need to find that out...