Let $W$:$=\{(x,y,z)$:$x^2+y^2+z^{2}9,\sqrt[\phantom{2}]{x^2+y^2}z\}sub{R}^3.$

$($a$)$ Describe $W$ in Cylindrical coordinates.

$($b$)$ Describe $W$ in Spherical coordinates.

$($c$)$ Compute the volume of $W,$ and ${}_{W}z.$