00:02
The thermal efficiency, n, is equal to 1 minus t cold or divided by t hot.
00:08
So our n is 1 minus 300 divided by 750, which is 60%.
00:15
So that's our thermal efficiency of our cycle.
00:18
We'd like to find the work and heat transfer.
00:22
So our volume, we can calculate the volume at the beginning of our isothermal expansion process.
00:32
Q12 is equal to mr -th ln of v2 over v1.
00:39
So if we plug in, we have ln 0 .4 over v1 is equal to 60 divided by 2 times 0 .287 times 750.
00:50
So v1 is 0 .347 meters cubed.
00:56
So that's the volume at the beginning of our process.
00:59
P2, we can determine the pressure using the ideal gas model.
01:05
P2 is mrt2 divided by v2.
01:11
So p2 is 1076 .2 kpa.
01:17
Now the pressure at the beginning of the process, we use p1v1 is equal to p2v2.
01:23
So plugging in, p1 is equal to 1237 .3 kpa.
01:34
Now, let's calculate the work and heat transfer.
01:39
So we know delta u12 is equal to q minus work.
01:46
And but delta u is just mcv t2 minus t1 is equal to q minus work.
01:53
But since t1 is equal to t2, we find work 12 equal to 60 kilojoules...