Two point charges of and are fixed apart in vacuum

PHYSICS · Subjective · AP · Physics 2: Algebra-based · Electric Force Field and Potential · Electric Force Field and Potential

Problem

Two point charges of

+5\,\mu\text{C}

and

+20\,\mu\text{C}

are fixed

40\,\text{cm}

apart in vacuum. Calculate the distance from the

+5\,\mu\text{C}

charge at which a

+1\,\mu\text{C}

test charge must be placed on the line joining the two charges so that the net electrostatic force on it is zero.