question_answer

  A bullet of mass 20 g is horizontally fired with a horizontal velocity 150 from a pistol of mass 2 kg. What is the recoil velocity of the pistol?

Answer:

                  For bullet                 [By convention, the direction of bullet is taken from left to right (positive)] For pistol Total momenta of the pistol and bullet before the fire                                                       Total momenta of the pistol and bullet after the fire According to the law of conservation of  momentum, Total momenta after fire = Total momenta before the fire                                                         (1) Negative sign indicates that the direction in which the pistol would recoil is opposite to that of bullet (right to left),