A neutron have K.E. = 15eV suffers head on collision with hydrogen atom in ground state at rest then after collision K.E. of : (Assume mass of neutron same as that of hydrogen).
(A) Neutron is 1.4 eV
(B) Hydrogen is 1.4 eV
(C) Neutron is zero
(D) Hydrogen is 15 eV
