A neutron having kinetic energy 12.5 eV collides with a hydrogen atom at rest. Neglect the difference in mass between the neutron and the hydrogen atom and assume that the neutron does not leave its line of motion. Find the possible kinetic energies of the neutron after the event.

Q. A free hydrogen atom in ground state is at rest. A neutron of kinetic energy K collides with the hydrogen atom. After collision hydrogen atom emits two photons in succession one of which has energy $2.55eV$. Assume that the hydrogen atom and neutron has same mas.

Q. A neutron collides head-on and elastically with an atom of mass number $A$, which is initially at rest. The fraction of kinetic energy retained by neutron is

Q. A neutron is moving with velocity $u$. It collides head-on and elastically with an atom of mass number A. If the initial kinetic energy of the neutron is E, how much kinetic energy is retained by the neutron after the collision?

Q. A neutron travelling with a velocity $v$ and kinetic energy $E$ collides head on elastically with the nucleus of an atom of mass number $A$ at rest. The fraction of its kinetic energy retained by the neutron even after the collision is

Q. A neutron of kinetic energy $65eV$ collides inelastically with a singly ionized helium atom at rest. It is scattered at an angle of ${90}^{\circ }$ with respect to its original direction.
Find the allowed values of the energy of the neutron and that of the atom after the collision.
[Given : Mass of $Heatom=4\times$ (mass of neutron) Ionization energy of $H$ atom $=13.6eV$]