Question

A 10-cm-long thin glass rod uniformly charged to 5.00 nC and a 10-cm-long thin plastic rod uniformly charged to - 5.00 nC are placed side by side, 4.00 cm apart. Whatare the electric field strengths to at distances 1.0 cm, 2.0 cm, and 3.0 cm from the glass rod along the line connecting the midpoints of the two rods?

E1:
E2:
E3:

Answer 1

q = 5.00 nC, L = 10 cm, d = 4.00 cm, r = 1.0 cm, or 2.0 cm, or 3.0 cm

E(r) = q/(2πε₀rL) + q/[2πε₀(d - r)L] = q/(2πε₀L) * [1/r + 1/(d - r)] = 900 [1/r + 1/(d - r)]

E₁=E(1.0 cm) = 1.20*10⁵N/C

E₂=E(2.0 cm) = 9.00*10⁴N/C

E₃=E(3.0 cm) = 1.20*10⁵N/C