Two point charges

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

Problem

Two point charges,

q

and

2q

, are separated by a distance

r

. The electric potential energy of the pair is

0.90\,\text{J}

. After the charges are moved

0.10\,\text{m}

closer together, their potential energy becomes

1.20\,\text{J}

. Determine the initial separation

r