Physics - Circular motion question..please help me..:( A ball of mass 0.50kg is swung in a circle of radius 2.0m with a period of 1.5s. a.) what is the speed of the ball? b.) what is the acceleration of the Ball? C.) What centripetal force must be exerted by the string that keeps the ball in orbit? d.) what is the mass of the central object? e.) What angle does the string make with the veritical? f.) how long is the strong, L? Thanks so much if u can help...it would be good to show me the explanation and the formulas used as well...thanks a bunch!