P$\mathrm{.}9-15$ A generator with an open$-$circuit voltage o$9($t$)=10$ sin $8000$ret $($V$)$ and internal impedance Z$9=40+$J$30(12)$ is connected to a $50(12)$ distortionless line. The line has a resistance of $0\mathrm{.}5(12/$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, and