Question

In a rectangular coordinate system, a positive point charge q = 7.50 nC is placed at the point x=0.230 m , y=0, and an identical point charge is placed at x= -0.230 m , y=0. Find the x and ycomponents and the magnitude and direction of the electric field at the following points.

Find the x and y components of the electric field at x= 0.230 m , y= -0.350 m .

Find the magnitude of the electric field at x= 0.230 m , y= -0.350 m .

Find the directiion of the electric field at x= 0.230 m , y= -0.350 m .

Answer 1

a)
E1 = k*q1/r1^2

= 9*10^9*7.5*10^-9/0.35^2

= 551 N/C (towards -y axis)

E2 = k*q2/r2^2

= 9*10^9*7.5*10^-9/((2*0.23)^2 + 0.35^2 )

= 202 N/C (below +x axis)

Ex = E1x + E2x

= 0 + 202*2*0.23/sqrt((2*0.23)^2 + 0.35^2 )

= 161 N/c <<<<<<<-----Answer

Ey = E1y

= -551 N/c <<<<<<<-----Answer

b) |E| = sqrt(Ex^2 +Ey^2)

= sqrt(161^2 + 551^2)

= 574 N/c

c) direction : theta = tan^-1(Ey/Ex)

= tan^-1(-551/161)

= 73.7 degrees below +x axis