Answer:
Explanation:
We know that the thermal efficiency is the ratio of work done by the engine over the heat taken
[tex]\eta = \frac{W_{made}}{Q_{in}}[/tex]
Now, how much work the engine do in a cycle?
We know that the work done in a cycle must be equal to the heat taken minus the heat rejected
[tex]W{made} = Q_{in} - Q_{rejected}[/tex]
So, the thermal efficiency will be:
[tex]\eta = \frac{Q_{in} - Q_{rejected}}{Q_{in}}[/tex]
[tex]\eta = \frac{Q_{in}}{Q_{in}} - \frac{Q_{rejected}}{Q_{in}}[/tex]
[tex]\eta = 1 - \frac{Q_{rejected}}{Q_{in}}[/tex]
Putting the values of the problem
[tex]\eta = 1 - \frac{259.8 kJ }{441.3kJ}[/tex]
[tex]\eta = 0.4113[/tex]
