Data : KE = 5 × 10-21 J, m = 1.675 × 10-27 kg, h
= 6.63 × 10-34 J∙s
KE = \(\cfrac{1}2\) mv2 = 5 x 10-21 J
∴ v = \(\sqrt{\cfrac{2KE}m}\) = \(\sqrt{\cfrac{(2)(5\times10^{-21})}{1.675\times10^{-27}}}\)
= 2.443 × 103 m/s
This is the speed of the neutrons. The de Broglie wavelength associated with the neutron,