Answer
(a) greater than $0.47$
(b) $0.488$
(c) $512J$
Work Step by Step
(a) We know that
$e=1-\frac{T_c}{T_h}$
We plug in the known values to obtain:
$e=1-\frac{295K}{576K}$
$e=0.488$
The new efficiency is greater than $0.47$.
(b) We can find the new efficiency as
$e=1-\frac{T_c}{T_h}$
We plug in the known values to obtain:
$e=1-\frac{295K}{576K}$
$e=0.488$
(c) We can find the required work done as follows:
$W=eQ_h$
We plug in the known values to obtain:
$W=(0.488)(1050J)$
$W=512J$
