$16-53$ An electronic package with a surface area of $1$ m$2$ placed in an orbiting space

station is exposed to space. The electronics in this package dissipate all $1$ kW of its

power to the space through its exposed surface. The exposed surface has an emissivity

of $1\mathrm{.}0$ and an absorptivity of $0\mathrm{.}25.$ Determine the steady$-$state exposed surface

temperature of the electronic package $($a$)$ if the surface is exposed to a solar flux of

$750$ W$/$m$2,$ and $($b$)$ if the surface is not exposed to the sun