Answer
$v=1.48\times 10^7\frac{m}{s}$
Work Step by Step
According to law of conservation of energy;
$K.E=\Delta U$
$\implies \frac{1}{2}mv^2=q\Delta V$
This simplifies to
$v=\sqrt{\frac{2q \Delta V}{m}}$
We plug in the known values to obtain:
$v=\sqrt{\frac{2(1.6\times 10^{-19})(625)}{9.109\times 10^{-31}}}=1.48\times 10^7\frac{m}{s}$
