Question

What is the wavelength associated with an electron moving with a velocity of $4\times {10}^{7}m{s}^{-1}$?

Answer 1

The wavelength of an object of mass 'm' moving with a velocity 'v' is given by:

$\lambda =\frac{h}{mv}$

where 'h' is the plank's constant

The wavelength associated with an electron moving with a velocity of $\mathrm{4 \times 10^7 \ ms^{-1}} is given by:

$\lambda =\frac{h}{m_e{v}_e}$

$m_e=9.1\times {10}^{-31}kg\&v_e=4\times {10}^{7}m{s}^{-1}$

$⟹\lambda =\frac{6.62\times {10}^{-34}}{9.1\times {10}^{-31}\times 4\times {10}^7}m=0.18\times {10}^{-10}m=0.18\mathring{A}$