Question

. Charge q1= 1.80*10-8 C is placed at the origin O. Charge q2 = -7.20*10-8 C is placed at point A ( x =0.180 m) as shown in the figures. a.

A charge q3 = 2.5 *10^-8 C is placed at point B ( x = 0.0900 m) as shown in fig.a. Determine the net force F3 exerted on charge q3 by q1 and q2. Give your answer unit vector notation. b. The charge q3 is now placed at point C ( x = 0.270 m) as shown in fig.b. Determine the net force F3 exerted on charge q3 by q1 and q2. Give your answer unit vector notation. c. Find the coordinate xD of a point D on the negative x-axis for which of the net force F3 exerted on q3 by q2 and q1 is zero. Use fig.c. q1 q 3 q2 x fig.a O B A.

Answer 1

This question deals with the simple eletrostatic force equation.

The coloumb law gives us the force between two charges.

  ke is Coulomb's constant (ke ≈ 9×109 N⋅m2⋅C−2) q1 and q2 are the signed magnitudes of the charges, and the scalar r is the distance between the charges.

The superpostion of electrostatic force gives us force one a particular charge is,

a)Thus we want to find F3. F13 is in negative X direction, F23 is in positive X direction.

using the above equation we have the resultant force is in the negative X direction.

b)Now both F13 is in the positive X direction and F23 is to negative X direction.

Thus after the summation we have

The force is now drected to the positive X direction.

c) We want to find the coordinate on negative X axis for which F3 is zero, I hope the charge q3 is only changed the negative X axis. This question have a little ambiguity, please correct it I am unable to answer this