The distance between the charge and the source of the electric field is 2.2 m.
The potential energy <em>U</em> of a charge <em>q</em> placed in an electric field created by a source charge <em>Q</em>, at a distance <em>r</em> from the source charge is given by,
...... (1)
Here, <em>k</em> is the Coulomb constant.
The electric field <em>E</em> at a distance <em>r</em> from the source charge is given by,
......(2)
From equations (1) and (2)
Rewrite the expression for <em>ri.</em>
Substitute 75 J for <em>U</em>, for <em>E</em> and for <em>q</em>.
Rounding off to the nearest tenth, the the distance between the charge and the source charge is 2.2 m