Answer:
3 m/s
Explanation:
The momentum of an obejct is given by
[tex]p=mv[/tex]
where
m is the mass of the object
v is the velocity of the object
For the ball in this problem, we know:
[tex]p = 12 kg m/s[/tex] is the momentum
[tex]m=4 kg[/tex] is the mass
Therefore, we can re-arrange the equation to find v, the velocity of the ball:
[tex]v=\frac{p}{m}=\frac{12 kg m/s}{4 kg}=3 m/s[/tex]