Use the spherical co$-$ordinates to evaluate

${}_E\sqrt[\phantom{2}]{x^2+y^2+z^2}$

where $E$ lies above the cone $z=\sqrt[\phantom{2}]{x^2+y^2}$ and between the sphere $x^2+y^2+z^2=1$ and $x^2+y^2+z^2=4.$