posted by stacy .
A charged line extends from y = 2.50 cm to y = -2.50 cm. The total charge distributed uniformly along the line is -9.00 nC. Find the magnitude of the electric field on the x-axis at x = 0.25 cm.
The charge per unit length is
-9*10^-9C/0.05m = =1.8*10^-7 C/m
You will have to perform an integration of Coulombs law for the E-field along the x axis at x = 0.25. There will be no y component, due to symmetry.
dE = k*(charge density)*x*dy/(x^2+y^2)^(3/2)
Integrate from y=-0.025 to +.025 m, with x fixed.