Physics question about rc power

I attach a voltage source to a 40 mF capacitor until it is fully charged. I then take the voltage source away and discharge the capacitor through a 110  resistor in a basic RC circuit. If the initial current through the circuit during discharge is 05 A, what voltage did I apply to the capacitor to charge it? 

Correct: 55 V 

How much energy does the resistor dissipate as heat between t=0 s and t=3 s ? Note that there are at least two ways to do this problem, one of which doesn't require your answer from the first part. If you're not confident in that answer, try to find another way. 


Correct: 450 J