Final answer:
If an object has a negative velocity, its momentum will be negative as well because momentum is calculated by multiplying the object's mass by its velocity, and mass is a scalar quantity.
Step-by-step explanation:
When an object has a negative velocity, this indicates that the direction of its velocity vector is opposite to the chosen positive direction. Since momentum is a vector quantity similar to velocity and is calculated by multiplying an object's mass (a scalar) by its velocity (a vector), the sign of the object's momentum will align with the sign of its velocity. Therefore, if the velocity is negative, the momentum will also be negative.