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# Three people are observing the same car. One person claims that the car’s momentum is positive, another person claims that it is negative, and the third person says that it is zero. Can they all be right at the same time? Explain.

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$\textbf{We know that the Momentum is a vector quantity which is given by}$

$\vec p=m\vec v$

If the car is moving to the right and you are standing on the ground, then you will see that the car is moving toward the positive x-direction. This means that the velocity of the car is pointing toward the positive x-direction. Since the momentum is a vector quantity and its direction depends on the direction of the velocity, then the momentum of the car is also pointing toward the positive x-direction.

Therefore, you can say that the car's momentum is positive.

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