A capacitor consisting of two concentric spheres of radius R1 and R2 = 2.50·R1 has a capacitance of C = 6.00 picoFarads and is charged to a potential difference of 74.0 Volts.
Calculate the energy stored in the capacitor.
Calculate the charge on this capacitor, when the electrical energy stored is 19.9·10-8 Joules.
If the radius of the outer sphere is increased by a factor of 3.00 while keeping the charge on the plates constant, by what factor does the stored energy change?
I've already answered #1 and #2 Questions, but I don't know how to calculate the third one. Help please!