Well, I tried and it doesn't work. Here's why:
Contrary to popular beleif, PowerTower isn't a freefall ride...it has a controlled decent which is faster than freefall. The result, an object held out at the top will fall slower than you will, strapped into the car. Moral of this story is, make sure you hold your arm wayyyy out because otherwise, that quarter is gonna hit you on it's way down and you'll be on the upward bounce and it'll hurt. Don't try, it won't work...
Later
seth