Point charges $q_1=50C$ and $q_2=-25C$ are placed $1\mathrm{.}0m$ apart on the $x-$axis with $q_2$ at a more positive $x$ coordinate. $($a$)$ What is the electric field at a point midway between them $($vector so give magnitude AND direction$)?($b$)$ What is the force on a charge $q_3=20C$ if it is subsequently placed there $($vector$,$ so give magnitude AND direction$)?$