An object that is 0.5 m above the ground has the same amount of potential energy as a spring that is stretched 0.5 m. Each distance is then doubled. How will the potential energies of the object and the spring compare after the distances are doubled? The gravitational potential energy of the object will be two times greater than the elastic potential energy of the spring. The elastic potential energy of the spring will be four times greater than the gravitational potential energy of the object. The elastic potential energy of the spring will be two times greater than the gravitational potential energy of the object. The potential energies will remain equal to one another.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach