Alright guys, so let's take a look at our example problems. So we have this gas that's undergoing this cyclic thermodynamic process in our PV diagram. And we want to do is calculate the total amount of heat that's added over a complete cycle. So basically we just want to figure out well what is Q total? Now? There's a couple of ways you might think about this. You might think well the total amount of heat is just gonna be if I add together the heat from all of the processes. So, for example, this is gonna be cue from A to B plus que from B to C plus que from C back to a. Now you might be thinking this because well, let's see, B two C is an ice. A barrack process, that's S O. P. And so therefore we have an equation for that. Right? So we could probably figure that out. This is the C2 a process is going to be a nicer volumetric and we also have an equation for that. The trouble is we don't really have an equation when it comes to this A to B process. This isn't one of our special processes. So we don't have an equation to calculate just the heat for that. Alright, so this actually is not gonna work because there's no way to to figure out what QA B is. So this actually isn't going to work. And instead we're going to have to think about another property of cyclic processes. That's going to help us. So remember that for cyclic process, the change in the internal energy is always equal to zero. If you start and end in the same place on a PV diagram, there's no change in internal energy. So remember what that means. Is that the Q. Over the cycle is equal to W over the cycle, right? By the first law of thermodynamics. So really this Q over the cycle here is actually just gonna be equal to the total amount of work that's done in this in this cyclic process here. Remember that is actually pretty easy to calculate because the work done over the cycle is actually just the area that is inside of the loop that the sort of cycle runs around. Right? So really this is equal to the work done over the cycle and it's also equal to the heat that's added over the cycle. Those mean the same exact thing. So really this is just gonna be the area that's inside of the loop. And we have a couple of different ways. We can figure this out right? Since we have all the values for pressure and volume. We can kind of just use the area of a triangle like this, right? It's just a triangle. So we can use the area which is 1/2 base Times height. So let's just say that this is the heights, let's just say that this is the base like this. So really what happens is that Q. For the cycle is going to equal one half. Now the base here goes from four back to one. So the base here is going to be three and then the height of this thing is gonna be the difference between 40 and 10. So this base here is three and the height here is 30. So I'm just gonna do one half of three times 30. And what I'm gonna get here is 45 jewels. All right. Now we're missing one thing here. We're missing the rules for whether the work is positive or negative, remember that? This work cycle here. If it's clockwise, the work done over, the cycle is going to be Positive. If it's counterclockwise, the work done by the cycle is going to be negative. What do we have here? We have a loop that's running counterclockwise, it's this one here. So therefore our answer has to have a negative sign. It's going to be negative. 45 jewels for the work. And also the heat added over the cycle. So basically what this means here, is that more heat is removed from this cycle here than it is added over. And so the overall heat is going to be negative 45. All right, So that's this one. Let me know if you have any questions