Physics

Problem

A neutron in thermal equilibrium at a temperature of

300\,\text{K}

has an average translational kinetic energy of

\tfrac{3}{2}k_{\!B}T

(Boltzmann constant

k_{\!B}=1.38\times10^{-23}\,\text{J\,K}^{-1}

; neutron mass

1.67\times10^{-27}\,\text{kg}

). Calculate its de Broglie wavelength. a)

1.78\,\text{\AA}

1.45\,\text{nm}

1.45\,\text{\AA}

0.23\,\text{\AA}