At what separation should two equal charges, 1.0C each, be placed so that the force between them equals the weight of a 50 kg person?
Given:
Mass of the person 
Weight of the person, 
Charges: 
Formula used:
By Coulomb’s law, the electric force is given by:
Where ϵ0 is the permittivity of free space
q1 and q2 are the magnitude of charges
r is the distance of separation between the charges
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The magnitude of electric force is given by:
Rearranging, we get
Note that 
Substituting all the values, we get
1