A rubber stopper, which has a mass of m = 14.5 grams, is tied to the end of a string which is threaded through a glass tube. You then spin the rubber stopper about your head in a horizontal circle as shown to the right. The stopper sags  = 18.0o below the horizontal as shown and the distance from the top of the tube to the stopper is L = 1.25 m.
b. What will be the magnitude of the centripetal force acting on the stopper?
c. What is the speed of the stopper?
d. What is the tension in the string?
e. How much Mass M is hanging on the end of the string?