You would have to look for the mass of the sample and the volume of the sample.
If P=M*V than P=30kg*5m/s. P=150.
P=momentum
M=mass
V=Velocity
Now the last time i have done physics was last year. but i'm pretty confident in this answer. Hope this helps!
2 the answer is 2 because 1.0 * 2 =2
Definitely definite mass because liquids can take on any shape and can have different volumes.