$m_{p^+}$=$1.66\cdot 10^{-27}\;kg$; $m_{e^-}$=$9.11\cdot 10^{-31}\;kg$ What is the ratio of the wavelengths of the electrons and protons when both have half the speed of light velocity?
Electron: $\lambda_{e^-}$ $=$ $\frac{h}{m_{e^-}v}$ Proton: $\lambda_{p^+}$ $=$ $\frac{h}{m_{p^+}v}$ $\frac{\lambda_{e^-}}{\lambda_{p^+}}$ $=$ $\frac{\frac{h}{m_{e^-}v}}{\frac{h}{m_{p^+}v}}$ $=$ $\frac{m_{p^+}}{m_{e^-}}$ $=$ $\frac{1.66\cdot 10^{-27}}{9.11\cdot 10^{-31}}$ = $1822$
