posted by Nelly .
A simplified model for an erythrocyte is a spherical capacitor with a positive inner surface of area A and a membrane of thickness b. Use potential difference of 98 mV across the membrane and a dielectric constant K = 5.0. If the capacitance of the membrane is C = 0.27 pF, what is the radius of the erythrocyte? The thickness of the membrane is b = 90 nm.