Charge q_1 = -4.5 nC is located at the coordinate system origin, while charge q_
ID: 584642 • Letter: C
Question
Charge q_1 = -4.5 nC is located at the coordinate system origin, while charge q_2 = 0.89 nC is located at (a. 0). where a - 1.1 m. The point P has coordinates (a. b). where b = 0.45 m. A third charge q$ = -1.5 nC will be placed later. Find the electric potential Vp 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
q1 = -4.5 nC
q2 = 0.89 nC
a = 1.1 m
b = 0.45 m
q3 = -1.5 nC
(a)
Electric Potential at Point p,
Vp = k*q1/r1 + k*q2/r2
Vp = (- 8.9*4.5)/(sqrt(1.1^2 + 0.45^2)) + (8.9*0.89)/(0.45)
Vp = - 16.1 v
(b)
W = q* Vp
W = -1.5*10^-9 * 16.1
W = 2.415 * 10^-8 J
(c)
U = k*q1q2/r + K*q1q3/r + k*q2q3/r
U = 8.9* 10^-9[(-4.5*0.89)/1.1 +(4.5*1.5)/sqrt(1.1^2+0.45^2) + (-1.5*0.89)/0.45 ]
U = -8.26 * 10^-9 J