Here's why:
* Momentum is defined as the product of mass and velocity: Momentum (p) = mass (m) * velocity (v)
* If velocity remains constant, any change in momentum is directly related to the change in mass.
* As mass decreases, momentum decreases proportionally.
Example:
Imagine a rocket in space. It expels fuel, causing its mass to decrease. However, its velocity remains constant. Since its mass is decreasing, its momentum is also decreasing.
Important Note: This assumes that the mass decrease is slow enough that the change in velocity is negligible. If the mass decreases rapidly, the velocity might also change, leading to a more complex situation.
