Question

Positive charge Q is distributed uniformly along the x-axis fromx=0 to x=a. A positive point charge q is located on the positivex=axis at x = a+r, a distance r to the right end of Q.

 

(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/(4pi epsilon0 r^2). Explain why this result is obtained.