A stone is dropped from the top of a high cliff with zero initial velocity. In which system is the net momentum zero as the stone falls freely

A system of stone and earth can result to a net zero momentum.

The principle of conservation of linear momentum states that the sum of the initial momentum is equal to the sum of final momentum.

A system that consists a linear system of stone and earth can result to a net zero momentum.

Thus, a system of stone and earth can result to a net zero momentum.

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A system that includes the stone and the earth.

Explanation:

If the system of being dropped from the height of the cliff consists of just the stone alone, then it means that its momentum will certainly undergo changes as it falls freely. However, If the system is now expanded to include not only the stone but also the Earth, then it implies that the momentum of the stone which is in the downward direction will be equal and opposite to the momentum of the Earth in the upwards direction towards the stone. Therefore, the momentum will cancel out and net momentum will be zero.

thermal energy is the answer

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