6. A uniform positive charge distribution lies on the y axis as shown below in red. Determine

the x and y components of the electric field at a point P at a distance x to the right of the origin.

Take the linear charge density to be lambda which is given by Q/L where Q is the total charge and L is

the length of the charge distribution. Hint: write the vectors, r, r’ and u in i,j,k notation and use

the formula:


Figure 1:
Result

Figure 2:
Result

--> assume(x>0,k>0,%lambda>0,L>0);

Result

--> dE_x(yp):=k*%lambda*x*(x^2+yp^2)^(-3/2);

Result

--> dE_y(yp):=-k*%lambda*yp*(x^2+yp^2)^(-3/2);

Result

--> integrate(dE_x(yp), yp, -L,0);

Result

--> integrate(dE_y(yp), yp, -L,0);

Result

--> E_y(x,k,la,L):=k*la*(1/x-1/(x^2+L^2));

Result

--> wxplot2d([E_y(x,1,1,1)], [x,0,5], [y,0,20])$

Result

--> E_x(x,k,la,L):=k*la*L/x/(x^2+L^2)^(1/2);

Result

--> wxplot2d([E_x(x,1,1,1)], [x,0,5], [y,0,20])$

Result


Created with wxMaxima.