I am having some trouble with this problem, an explanation on how to do this would be awesome, thanks: The large blade of a helicopter is rotating in a horizontal circle. The length of the blade is 6.40 m, measured from its tip to the center of the circle. Find the ratio of the centripetal acceleration at the end of the blade to that which exists at a point located 2.86 m from the center of the circle. I just don't see how there's enough info. to solve this. Please explain.