question_answer 54)

  A light and a heavy object have the same momentum. Find out the ratio of their kinetic energies. Which one has a larger kinetic energy?

Answer:

  Suppose  and  are masses of a light and a heavy objects, respectively. As we know kinetic energy        [v = velocity of objects]                                                                                                                                                 ...(i) and   movement                          (p) = mv                                                                                                    ...(ii) Multiplying and dividing with m in Eqs. (i) So, as form Eqs (ii)                                                  So,                        We have,                  kinetic energy, Momentum is same for light and heavy body So,                          kinetic energy, Thus, kinetic energy is inversely proportional to the mass. So, lighter body has larger kinetic energy.