A neutron moving with a speed u strikes a hydrogen atom in ground state in ground toward it with the same speed Find the minimum speed of the neutron for which ineleastic (completely or perially) collision may take place .The mass of neutron = mass of hydrogen `= 1.67 xx 10^(-27)kg`

Answer

A, C, D

Explanation

Energy of the neutron is `1/2 mv^2`
The condition for inelastic collision is
`1/2mv^2 gt 2DeltaE`
implies `Delta E lt 1/4 mv^2`
Here Delta E is the energy absorbed.
Energy required for first excited state is `10.2 eV`.
:' `Delta E lt 10.2 eV`.
:' ` 10.2 eV lt 1/4 mV^2`
implies `v_(min) = sqrt((4 xx 10.2)/m)eV`
implies `v=sqrt((10.2 xx 16 xx 10^19 xx4)/(1.67 xx 10^-27))`
`=6 xx 10^4 m//sec`.