Difficulties with capacitor circuit analysis
At T&lt;0 Energy stored in C1 is 500u Joules

Joules = ½ QV
  where
     V=10V
     Q=(C * 10V)  so Q=10uF * 10V

At T1 and T2 simple use the decay function

where Vss is steady state (of 5 volts ...which is half of the orig 10 evenly divided between the caps)
and Vinit is 10 volts

I suspect each cap (ideally) will retain 5 volts each, as each could/should provide the same equilibrium (being the same size)