Explain why the magnetic field in solenoid is Greater if the solenoid has an iron core?

he magnetic field is greater because the magnetization of the material is added

Explanation:

The magnetic field in a solenoid is given by the relation

          B₀o = μ₀ n I

where n is the density of turns and I the current

When we put a magnetic material inside solenoid

the magnetic field is

         B = B₀ + μ₀ M

where M is called the magnetization of the material and corresponds to the alignment of the magnetic moments of the atoms with the field, therefore the total field is much greater, it should be noted that the part of Bo increases with the current, but the magnetization has a maximum value.

Consequently the magnetic field is greater because the magnetization of the material is added

we need to know the time interval during which the force acts. impulse of force = momentum change