Question

A 13.0 g piece of Styrofoam carries a net charge of â5.40 μC and floats above the center of a large horizontal sheet of plastic that has a uniform charge density on its surface. What is the charge per unit area (in C/m2) on the plastic sheet?

Answer 1

σ =4.180×10^{-9} C/m^2

Step-by-step explanation:

electric field due to non conducting sheet is

`E=(\sigma)/(2\epsilon_0)`

the force acting on the piece of Styrofoam

Eq= mg

⇒E= mg/q

now,

`(mg)/(q) = (\sigma)/(2\epsilon_0)`

⇒
`\sigma= (2mg\epsilon_0)/(q)`

`\sigma= (2*0.013*9.81*8.85*10^(-12))/(5.40*10^(-4))`

charge per unit area (in C/m2) on the plastic sheet σ =4.180×10^{-9} C/m^2