Question

Consider the figure given below. Charges q1, q2 and q3 are placed at A, B and C, respectively, and 1 2 3 2 C. q = q = −q = μ Determine the magnitude and the direction of the electric field at point P.

Answer 1

A +15 microC charge is located 40 cm from a +3.0 microC charge. The magnitude of the electrostatic force on the larger charge and on the smaller charge (in N) is, respectively,Answer: 2.5, 2.5 Solution: The magnitiude of the electrostatic for is given by, NcmCCCNmrQKQF53.2)40()3)(15)(/1099.8(2229221=×==μμ.Remember the force on 1 due to 2 is equal and opposite to the force on 2 due to 1. Problem 2:Two point particles have charges q1 and q2 and are separated by a distance d. Particle q2 experiences an electrostatic force of 12 milliN due to particle q1. If the charges of both particles are doubled and if the distance between them is doubled, what is the magnitude of the electrostatic force between them (in milliN)?Answer: 12 Solution: The magnitude of the initial electristatic force is mNdqKqFi12221==. The magnitude of the final electrostatic force is mNFdqqKFif12)2()2)(2(221===. Problem 3: Two identical point charges +Q are located on the y-axis at y=+d/2 and y=-d/2, as shown in the Figure. A third charge q is placed on the x-axis. At what distance from the origin is the net force on q a maximum