The momentum of a body of mass m kg traveling at a velocity v m/s is equal to M =m*v kg*m/s.
The total mass of the child and her wagon is 22 kg. Its velocity is 1.5 m/s. The momentum of the child and wagon is equal to 22*1.5 = 33 kg*m/s.
The momentum of a moving body is the product of the mass of the the body and the velocity of the body. Momentum is a vector quantity with direction same as the direction in which the body is moving.
For a body consisting of a child and a wagon with total mass 22 kg that is moving at a velocity 1.5 m/s, the magnitude of momentum is equal to 22*1.5 = 33 kg m/s
The momentum of a body of mass m kg traveling at a initial velocity u m/s is equal to M =m*u kg*m/s.
p = 22 * 1.5 = 33 kg m/s.