P$\mathrm{.}9-15$ A generator with an open$-$circuit voltage v$($t$)=10$ sin $8000$pi$*$t $($V$)$ and internal impedance Zg $=40+$j$30($ohms$)$ is connected to a $50($ohms$)$ line. The line has a resistance of $0\mathrm{.}5($ohms$/$m$),$ and its lossy dielectric medium has a loss tangent of $0\mathrm{.}18\%.$ The line is $50($m$)$ long and is terminated in a matched load. Find $($a$)$ the instantaneous expressions forthe voltage and current at an arbitrary location on the line, $($b$)$ the instantaneous expressions for the voltage and current at the load,