It should be impossible to brace yourself in mid-air, but Bruce was able to do that, concentrating his energy into the front of his forcefield and withstanding the battering ram.

Okay, Bruce, think. Doctor Spectrum... looks like he's got the same kind of Power Prism as the other ones... Weaknesses... Ultra-violet light.

Bruce's powers came from absorbing solar energy, though he could absorb other forms as well. And, of course, in absorbing solar energy... there was a lot of ultra-violet energy.

He brought his hands forward and unleashed a focus blast of ultra-violet light.