$5\mathrm{.}28$ WP A power cycle operates between hot and cold reservoirs

at $600$ K and $300$ K$,$ respectively. At steady state the cycle develops

a power output of $0\mathrm{.}45$ MW while receiving energy by heat transfer

from the hot reservoir at the rate of $1$ MW$.$

a$.$ Determine the thermal efficiency and the rate at which energy

is rejected by heat transfer to the cold reservoir, in MW$.$

b$.$ Compare the results of part $($a$)$ with those of a reversible power

cycle operating between these reservoirs and receiving the same

rate of heat transfer from the hot reservoir.