Chapter 21, Problem 21.79P

CALC Positive charge Q is distributed uniformly along the x-axis from x = 0 to x = a. A positive point charge q is located on the positive x-axis at x = a + r, a distance r to the right of the end of Q (Fig. P21.79). (a) Calculate the x- and y-components of the electric field produced by the charge distribution Q at points on the positive x-axis where x > a. (b) Calculate the force (magnitude and direction) that the charge distribution Q exerts on q. (c) Show that if r >> a, the magnitude of the force in part (b) is approximately Qq/4π∈₀r². Explain why this result is obtained.

Figure P21.79