Answer:
c. 400 J
Explanation:
The efficiency of a Carnot Engine is given by:
[tex]\eta = 1 - \frac{T_C}{T_H}[/tex]
where in this case we have
[tex]T_C = 20^{\circ} +273 =293 K[/tex] is the temperature of the cold reservoir
[tex]T_H = 215^{\circ} +273 =488 K[/tex] is the temperature of the hot reservoir
Substituting into the equation,
[tex]\eta = 1 - \frac{293 K}{488 K}=0.40[/tex]
But the efficiency can also be written as
[tex]\eta = \frac{W_{out}}{Q_{in}}[/tex]
where
[tex]W_{out}[/tex] is the useful work in output
[tex]Q_{in}[/tex] is the heat absorbed by the hot reservoir
Here,
[tex]Q_{in} = 1000 J[/tex]
So solving the formula for [tex]W_{out}[/tex] we find
[tex]W_{out} = \eta Q_{in} = (0.40)(1000 J)=400 J[/tex]
