Answer
$1.63\times10^7\frac{m}{s}$
Work Step by Step
The kinetic energy of the particle is given. Solve for the speed. We assume this is a non-relativistic particle.
$$\frac{1}{2}mv^2=KE$$
$$v=\sqrt{\frac{2KE}{m}}=\sqrt{\frac{2(5.53\times 10^6eV)(1.60\times10^{-19}J/eV)}{6.64\times10^{-27}kg}}$$
$$=1.63\times10^7\frac{m}{s}$$
