I was wondering if one on you could answer this question.
Imagine a person standing on a spinning merry go round. The friction exerted by the floor is the centrifugal force that keeps the person spinning in a circle. As the speed is building up, the person needs to lean back more and more because i guess the friction force on his feet would tend to rotate the person about his centre of mass and this effect needs to be canceled by gravity. But the gravity exerts a force in the centre of mass so it cant offset the moment created by the friction. So why does the person need to lean back?