A proton moving with 25% of the velocity of light is having a mass of 1.6 × 10^-24g. What is the de Broglie wavelength associated with the proton?

$\begin{array}{l}\mathrm{m}=1.6\times {10}^{-24}\mathrm{g}\\ \mathrm{V}=3\times {10}^{10}\mathrm{cm} {\sec }^{-1}\times \frac{25}{100}\\ =0.75\times {10}^{10}\mathrm{cm}{\text{\hspace{0.17em}sec }}^{-1}\end{array}$

The de Broglie wavelength associated with the proton is 

$\begin{array}{l}=\frac{6.626\times {10}^{-27}\mathrm{ergsec}}{1.6\times {10}^{-24}\times 0.75\times {10}^{10}}\\ =5.52\times {10}^{-13}\mathrm{cm}\end{array}$