Suppose a ball of mass m is thrown vertically upward with an initial speed v, its speed decreases continuously till it becomes zero. Thereafter, the ball begins to fall downward and attains the speed v again before striking the ground. It implies that the magnitude of initial and final momentums of the ball are same. Yet, it is not an example of conservation of momentum. Explain why?
ScienceClass 9CBSEAnswered 27 Mar 2026
Answer
If external force did not act on the system momentum of that system remains constant. In the give case change in velocity is due to gravitation force of the earth.
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