Problem 27.9 Two 10-cm-long thin glass rods uniformly charged to +10nC are placed side by side, 4.0 cm apart.
What are the electric field strengths E1, E2, E3 and at distances 1.0 cm, 2.0 cm, and 3.0 cm to the right of the rod on the left, along the line connecting the midpoints of the two rods?
Eline= 1/4πε0 * 2|λ|/r
The Attempt at a Solution
I understand that the Electric field at the midpoint would be zero. Point one and two will have the same strength but different directions.
I believe point one could be calculated by E1-(E3/3
Since the linear, uniform charge is inversely, linearly porportional.
For E1 I get 1.8E5 N/C; so, 1.8E5 N/C -(1.8E5N/C / 3) = 1.2E5 N/C
Mastering Physics reports the answer as 1.25E5 N/C