Mary and her younger brother alex decide to ride the 17-foot diameter carousel at the state fair. mary sits on one of the horses in the outer section at a distance of 6.5 feet from the center. alex decides to play it safe and chooses to sit in the inner section at a distance of 6 feet from the center. what is mary's centripetal acceleration am compared to that of alex's centripetal acceleration aa? give your answer as a multiple of aa aa