Does the size of the magnetic field change with the size of the magnet?

Not all of the time, it can also depend on the strength of the magnet.

Explanation:

say you have a small very strong magnet, that might work just as well as a large but week magnet.

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.