I.10.21 Flux of the vector field

condition: Calculate the flux of the vector field \[ \vec{a}=2 x \vec{\imath}-(x+y) \vec{\jmath}+z^{2} \vec{k} \] a) through the full surface of the cylinder \( V \) b) through the upper base of the cylinder \( V \), where \[ \vec{a}=2 x \vec{\imath}-(x+y) \vec{\jmath}+z^{2} \vec{k}, \quad V:\left\{\begin{array}{l} x^{2}+z^{2}=4 \\ y=0, y=2 \end{array}\right. \]