Q. A nucleus of uranium decays at rest into nuclei of thorium and helium. Then :
A) The helium nucleus has less kinetic energy than the thorium nucleus
B) The helium has more kinetic energy than the thorium nucleus.
C) The helium nucleus has less momentum than the thorium nucleus.
D) The helium nucleus has more momentum than the thorium nucleus.
Explanation
[Solution] Momenta are equal and opposite; $K = \frac{p^2}{2m}$, so the lighter helium nucleus has more kinetic energy. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.