Question

7. Three charges are arranged in a straight line. The first charge has a charge of 9.0 microcoulombs, the middle charge has a charge of -12.0 microcoulombs and is 45 cm from the first charge, and the third charge has a charge of 15.0 microcoulombs and is 15 cm from the middle charge (opposite side from the first charge). First, draw a picture of the charges (similar to figure 16-19) with an x-axis. Calculate the net force acting on the first charge due to the other two charges. Remember to give the direction relative to your x-axis. For the same arrangement of charges as in problem 7, calculate the electric field strength at the position of the first charge due to the other two charges. 8.

Answer 1

In this problem we have to find net force on charge one due to other two charges.

Forces due to both charges will be along same staright line but in opposite direction.So we will take difference.

And F=QE where F is force Q is charge and E is electric field

In this problem we have to find net force on charge one due to other two charges. Forces due to both charges will be along same staright line but in opposite direction.So we will take difference. And F = QE where F is force Q is charge and E is electric field (7) F_net = -K theta_1 theta_2/(-45)^2 - K theta_1 theta_3/(-6)^2 Net force on 1st charge = k(9 times 10^-6) (12 times 10^-6)/(-45)^2 - K(9 times 15) (10^-12)/(0.6)^2 = 1.425 i^hat N towards positive x - axis (towards right) (8) Electric field strength at position of first charge = F/theta_1 = 1.425/9 times 10^-6 N/C E = 1.583 times 10^5 N/C towards right