3. (10 points) A cylindrical capacitor consists of two long, coaxial, metal cylinders of radii R and R (R < R2) and the same length L, as shown below. Imagine for the moment that the inner cylinder has a total charge of +Q and the outer cylinder has a total charge of -Q. L R R2 P. a. (4 points) Use Gauss' Law to calculate the electric field at the point P in the diagram above, which is a distance r away from the axis. b. (4 points) Calculate the potential difference between the outer and the inner cylindrical shell. Which shell is at a higher electric potential? c. (2 points) Determine the capacitance of the cylindrical capacitor.