To calculate the magnetic force on a ball within a solenoid, one must consider the ball's material properties, particularly its magnetic permeability, and whether it is ferromagnetic or a permanent magnet. The magnetic field inside the solenoid is constant and can be significantly enhanced by inserting a highly permeable core, such as iron. When the current is turned off, the magnetic force disappears, and the ball will return to its initial position. If the current is activated with the iron core at rest just below the solenoid, the core will be pulled into the solenoid due to the magnetic attraction. Understanding these principles is essential for accurately calculating the force in Newtons acting on the object within the solenoid.