An engine executing a dual cycle has a compression ratio of $18$ and a cut$-$off ratio

of $1\mathrm{.}1.$ The pressure ratio during constant$-$volume heat addition process is $1\mathrm{.}1.$ At

the beginning of the compression, P$1=90$ kPa, T$1=17\backslash$deg C$,$ and V$1=0\mathrm{.}003$ m $3.$

Determine the net power produced by this engine using variable specific heats.