Question

Ball on Thread In Fig. 24-35, a small, nonconducting ball of mass m = 1.0 mg and charge q = 2.4 ✕ 10-8 C (distributed uniformly through its volume) hangs from an insulating thread that makes an angle θ = 10° with a vertical, uniformly charged nonconducting sheet (shown in cross section).Considering the weight of the ball and assuming that the sheet extends far vertically and into and out of the page, calculate the surface charge density σ of the sheet.

C/m2

Answer 1

θ =10

mass of the ball m =1*10^-6 kg

charge on the ball q = 2.4*10^-8 C

T = mg / cos ϴ

= 9.95*10^-6

E = T sinϴ /q = 71.99

The surface charge density on the sheet

σ = 1.7610^-11 *71.99 N/C

σ = 1.27*10^- 9 C/m^2