Answer: Hi! The definition of momentum is the "quantity of motion that an objet has", it means the product of the mass and velocity, so P = mv.
If the initial momentum is P₁ = m*v =20000 kg*m/s If we double the velocity, then P₂= m*2*v = 2*20000 kg*m/s = 40000 kg*m/s.
So if you multiply the velocity (or the mass) by any number, then you need to multiply the momentum by the same number.