The AC motor does exactly what you suggest it should. Additionally it acts as a brake when you take your foot off the accelerator. Effectively this means that when you want to get out of the cart you don't have a "parking" brake that others have. If you're not pushing the pedal, the car is stopped even on a hill. It is quiet and steers easily and runs the same speed on the flat, uphill, or downhill. There is a nice explanation at
Golf Cart Parts & Accessories From GolfCarCatalog.Com| which was written 6 years ago when the technology was new, but still, I believe, accurate as to the details of the AC motor