The electric potential V in the space between two flat parallel plates $1$ and $2$ is given $($in volts$)$ by V $=1500$x$2,$ where x $($in meters$)$ is the perpendicular distance from plate $1.$ At x $=1\mathrm{.}9$ cm$,($a$)$ what is the magnitude of the electric field and $($b$)$ is the field directed toward or away from plate $1?$