Question

1. why is momentum considered a vector quantity?

momentum is a quantity with only magnitude.
momentum is a quantity with both magnitude and direction.
momentum is a quantity with only direction.
momentum is a quantity with only time.

Explanation:

By definition, vector quantities possess both a measurable magnitude and a defined direction. Momentum, calculated as $\vec{p} = m\vec{v}$ (where $m$ is mass and $\vec{v}$ is velocity, a vector), has both a numerical size (magnitude) and a directional component matching the object's velocity, fitting the vector quantity criteria.

Answer:

Momentum is a quantity with both magnitude and direction.