Help with Capacitance!

Capacitor 2 has half the capacitance and twice the potential difference as capacitor 1.

What is the ratio (Uc)1/(Uc)2?

I have no idea how to go about starting this problem.

Thanks in advance!

I assume by U, it means the potential energy stored in the electric field of the capacitor.

The formula for that is: (1/2) C V^2
(http://hyperphysics.phy-astr.gsu.edu/hba…

So if C1 = C with potential V, then
C2 = 0.5 C, with potential 2V

U1 = (1/2) C V^2

U2 = (1/2) (1/2) C (2V)^2
U2 = (1/2) (1/2) C 4 V^2
U2 = 2 (1/2) C V^2
U2 = 2 U1

So the ratio U(C1) / U(C2) is 1/2.