The cell membrane in a nerve cell has a thickness of 0.12 micrometers. (a) Approximating the cell membrane as a parallel plate capacitor with a surface charge density of 5.9 x 10^(-6) C/m2, find the electric field within the membrane. (b) If the thickness of the membrane were doubled, would your answer to (a) increase, decrease, or stay the same. Explain. Can anyone help me get started on this? I think one of the formulas to use would be something like: E = sigma / permittivity of free space where E= electric field, sigma= charge density, and permittivity of free space= 8.85 x 10^-12 I am unsure how the membrane thickness comes into play.