1. The problem statement, all variables and given/known data The electric field strength just above one face of a copper penny is 2310 N/C. What is the surface charge density on this face of the penny? 2. Relevant equations Surface Charge Density = Q/A 3. The attempt at a solution The only thing that I can understand is that surface charge density is equal to Q/A but that does not seem to help me with this question. What can I do for this problem? Edit: I figured out how to do this problem.