On the way to school my brakes went out and i rear ended a teacher going 3mph,now says his engine is acting up?

If it's an older durango, it wouldn't surprise me. If you ever looked at what comes out of the pump, you would be disgusted at all the debris and sediment. This sediment collects in the base of the gas tank. When you rear-ended him, I'm uming his car was running at the time. So what probably happened, is that in the collision it stirred up the sediment, and the fuel pump sucked in some of that sediment, which could cause it to run rough. A bottle of fuel injector cleaner and it will be fine if that's the issue.