Charges on a coordinate system? Charge q_1 = -6.5 nC is located at the coordinat
ID: 1563002 • Letter: C
Question
Charges on a coordinate system?
Charge q_1 = -6.5 nC is located at the coordinate system origin, while charge q_2 = 3.43 nC is located at (a, 0), where a = 0.65 m. The point P has coordinates (a, b), where b = 0.95 m. A third charge q_3 = -1.5 nC will be placed later. Find the electric potential V_p at point P, in volts. Assume the potential is zero at infinity. How much work W, in joules, would you have to do to bring the third charge, q_3, from very far away to the point P? What is the total potential energy U, in joules, of the final configuration of three charges?Explanation / Answer
c)The potential energy of the final configuration is
U = K (q1q2/r12 + q2q3/r23 + q3q1/r31)
U = 9 x 10^9 x 10^-18 [-6.5 x 3.43/0.65 + 3.43 x -1.5/0.95 + -1.5 x -6.5/sqrt(0.95^2 + 0.65^2)] = -2.81 x 10^-7 J
Hence, U = -2.81 x 10^-7 J