question_answer

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 neutron after collision?

A) \[{{\left[ \frac{A}{\left( A+1 \right)} \right]}^{2}}E\]                   

B) \[{{\left[ \frac{A}{{{\left( A+1 \right)}^{2}}} \right]}^{{}}}E\]

C) \[{{\left[ \frac{\left( A-1 \right)}{{{\left( A+1 \right)}^{{}}}} \right]}^{2}}E\]       

D) \[{{\left[ \frac{\left( A-1 \right)}{{{\left( A+1 \right)}^{2}}} \right]}^{{}}}E\]