dentical $43$uC charges are fixed on an x$-$axis at x$=+/-3\mathrm{.}5$ m$.$ A particle of charge q$=-17$uC is then released from rest at a point on the positive part of the y$-$axis. Due to the symmetry of the situation, the particle moves only along the y$-$axis and has kinetic energy $1\mathrm{.}3$ J as it passes the point $(0,4\mathrm{.}0$m$).($a$)$ What is the kinetic energy of the particle as it passes through the origin $(0,0)?($b$)$ At what negative value of y will the particle momentarily stop?