Nisolated, irregularly shaped piece of platinum carries −7.71×10−9 c of charge and is in electric equilibrium. the size of this body is about 4 mm. when the electric potential at some point on the metal's surface has the value , the potential at a different point on the surface may equal . always differs from . equals . when the electric field strength at some point on the body's surface has the value , the field strength at a different point on the surface equals 0. equals . may equal . always differs from . calculate the potential at a distance of 6.41 m from the center of the charged piece of platinum. potential: