A $925$ mg particle carrying $1\mathrm{.}46$ mC of charge is shot into an electric field at $578\frac{m}{s}.$ Calculate the particle's acceleration while in the electric field if the field strength is $9\mathrm{.}50\frac{N}{C}.$ Ignore gravity.

In deep space, at a distance of $250.m$ from a charged particle, the electric potential is measured to be $-3\mathrm{.}25$ mV $.$ Calculate the charge on the particle.