Physics - Modern Physics Question with Solution | TestHub

Given, wavelength of light = 589 nm = 589 x 10^-9m

Mass of electron m_e= 9.1 x 10^-31kg

Mass of neutron m_n= 1.67 x 10^-27kg

Planck's constant h = 6.62 x 10^-34J - s

Kinetic energy of neutron

${\text{KE}}_{\text{n}}=\frac{{\text{h}}^2}{2{\lambda }^2{\text{m}}_{\text{n}}}$

$=\frac{{\left(6\text{.}63\times 10^{-34}\right)}^2}{2\times {\left(589\times 10^{-9}\right)}^2\times 1\text{.}66\times 10^{-27}}$

$=3\text{.}81\times 10^{-28}\text{ J}$.