Two point charges are lying on the y$-$ axis as in the figure: q$1=-4\mathrm{.}90\backslash$mu C and q$2=+4\mathrm{.}90\backslash$mu 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$0=7\mathrm{.}70\backslash$mu C and mass m $=1\mathrm{.}30$ g is placed at P$.$ When it is released, what is the magnitude of its acceleration?

$($a$)$ Number Units

$($b$)$ Number Units