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SAI INTERNATIONAL SCHOOL

                                           CLASS-IX   PHYSICS HOME ASSIGNMENT-11


                                                              OBJECTIVE

               MCQ(BOARD)

               1. In a rocket, a large volume of gases produced by the combustion of fuel is allowed to escape
               through its tail nozzle in the downward direction with the tremendous speed and makes the rocket

               to move upward.















               Which principle is followed in this take off of the rocket?


               (a) Moment of inertia



               (b) Conservation of momentum


               (c) Newton’s third law of motion


               (d) Newton’s law of gravitation


               2.A man wearing a bullet-proof vest stands on roller skates. The total mass is 80 kg. A bullet of
               mass 20 g is fired at 400 m/s. It is stopped by the vest and falls to the ground. What is then the
               velocity of the man?

               (a) 1 m/s


               (b) 0.1 m/s

               (c) 0.01 m/s


               (d) 0 m/s
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