The figure shows a thin rod of length L = 5.0 cm with total charge Q = 8.4 nC. What is the magnitude of the electric field E at x = 3.0 cm?
Figure in the attachment
E = Kq/r^2
K = 8.99 * 10^9 N m^2/C^2;
r is the distance between the point and the charge.
Field for a line of charge:
E = KQ/(d*(d^2 + (L/2)^2)^(1/2))
The Attempt at a Solution
We have Q, L and "d". But I am still unable to get the answer.
When I plug in the values as they are (as what I think they are), I get 64458.88
Answer is: 2.7*10^5 N/C.
But, when I use linear charge density lambda = Q/L.
E = lambda/4*pi*epsilon_0 * distance, I get 2.2634 N/C. Do you think this is the right way to get it?
I am not sure why that equation does not work.