Question

if the kinetic energy of a moving electron is 3*10-25 joule. calculate its wavelength

Answer 1

this equation is from debroglie hypothesis.

Answer 2

Answer : The wavelength of moving electron will be, $8.967\times 10^{-7}m$

Solution :

The relation between the wavelength an the kinetic energy will be,

Formula used :

$\lambda=\frac{h}{p}\\\\\lambda=\frac{h}{\sqrt{2\times m_e\times K.E}}$

where,

$\lambda$ = wavelength = ?

h = Planck's constant = $6.626\times 10^{-34}Js$

$m_e$ = mass of electron = $9.1\times 10^{-31}Kg$

K.E = kinetic energy of moving electron = $3\times 10^{-25}J$

Now put all the given values in the above formula, we get the wavelength of moving electron.

$\lambda=\frac{6.626\times 10^{-34}Js}{\sqrt{2\times (9.1\times 10^{-31}Kg)\times (3\times 10^{-25}J)}}$

$\lambda=8.967\times 10^{-7}m$

Therefore, the wavelength of moving electron will be, $8.967\times 10^{-7}m$