I.10.24 Flux of the vector field

condition: Find the flux of the vector field \( \vec{a}=y \vec{\imath}+x \vec{\jmath}+z^{3} \vec{k} \) through: a) the surface of the sphere \( x^{2}+y^{2}+z^{2}=9 \); b) section of this sphere by the plane \( x=\sqrt{5} \).