Answer
a. $1.7\times10^7\frac{m}{s}$
b. $1.3\times10^7\frac{m}{s}$
Work Step by Step
The kinetic energy of the particle is given. Solve for the speed. We assume this is a non-relativistic particle.
a. $\frac{1}{2}mv^2=KE$
$$v=\sqrt{\frac{2KE}{m}}=\sqrt{\frac{2(850eV)(1.60\times10^{-19}J/eV)}{9.11\times10^{-31}kg}}$$
$$=1.7\times10^7\frac{m}{s}$$
b. $\frac{1}{2}mv^2=KE$
$$v=\sqrt{\frac{2KE}{m}}=\sqrt{\frac{2(0.50\times 10^3eV)(1.60\times10^{-19}J/eV)}{9.11\times10^{-31}kg}}$$
$$=1.3\times10^7\frac{m}{s}$$
