My cousin was driving my Aurora Oldsmobile 1999 V8 engine we hit a dip at 25 miles per hour and now it's beeping saying low oil pressure. And the oil is full what damage could it be?

Maybe the oil pressure sender or the wiring that goes to it was damaged. Maybe somehow the oil pump was damaged. Take a look at the oil pan to see if there is a big dent in it.

It doesn't. What else do you think it can be?

Try changing the oil pressure sending unit.... they are about $15 and the bump caused it to fail....cheap thing to try. The sending unit is usually on or near the oil filter adaptor.