Answer:
The momentum of the soccer ball will be twice that of the baseball.
Explanation:
If an object of mass [tex]m[/tex] travels with a velocity of [tex]v[/tex], the momentum [tex]p[/tex] of that object will be [tex]p = m\, v[/tex]. Thus, if velocity is fixed, momentum will be portional to the mass of the object.
The mass of the soccer ball is twice that of the baseball: [tex](300 / 150) = 2[/tex]. Thus, when moving at the same velocity, momentum of the soccer ball will be twice that of the baseball.