2.1. Draw three diagrams. In the first diagram, draw a cell as a sphere with a very thin double wall, serving as the membrane of the cell. In the second

diagram, draw a zoom-in to a certain part of the cell membrane, as if you were zooming in to a small piece of the surface of the earth. In your diagram, justify why locally we can think of this surface as "flat," and see the two parts of the cell membrane as being parallel to each other. In the third diagram, draw your physics model, with a coordinate system. Set your origin to be equidistant from both the upper and lower plate, label the surface charged density, and set the vertical distance between the plates equal to d.