Two point charges are lying on the y$-$ axis as in the figure: q$1=-3\mathrm{.}40$ C and q$2=+3\mathrm{.}40$ C$.$ They are equidistant from the point P$,$ which lies on the x$-$ axis. $($a$)$ What is the magnitude of net electric field at P$?($b$)$ A small object of charge q$0=8\mathrm{.}00$ C and mass m $=1\mathrm{.}15$ g is placed at P$.$ When it is released, what is the magnitude of its acceleration?