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प्रश्न
A ball kept in a closed box moves in the box making collisions with the walls. The box is kept on a smooth surface. The velocity of the centre of mass
विकल्प
of the box remains constant
of the box plus the ball system remains constant
of the ball remains constant
of the ball relative to the box remains constant.
उत्तर
of the box plus the ball system remains constant
Consider the box and the ball a system. As no external force acts on this system, the velocity of the centre of mass of the system remains constant.
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