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Question
Internal forces can change
Options
the linear momentum but not the kinetic energy
the kinetic energy but not the linear momentum
linear momentum as well as kinetic energy
neither the linear momentum nor the kinetic energy
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Solution
the kinetic energy but not the linear momentum
Internal forces can not change the position of centre of mass of a system. Therefore, linear momentum of the system is constant, whereas kinetic energy of the system is not.
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