Question

if you double the mass of a moving object , the object's momentum is

Answer 1

since momentum = mass x velocity .
therefore 2 x (mass x velocity)= 2 x momentum.
therefore if we double the mass momentum gets doubled.

Answer 2

Momentum= mass × velocity
from this relation between momentum, mass and velocity we get
momentum is directly proportional to mass
Therefore when mass is doubled then momentum also get doubled