Problem 1. A child ties a 0.200-kilogram rubber stopper to the end of a cord and wants to whirl it in a horizontal circle of radius 0.75 meters at 1.5 revolutions per second. (a) Draw a free-body diagram of the stopper and show all the forces acting on it. (b) Show in a vector diagram (do not calculate) the net force acting on the stopper as it moves in a circle. (c) What would the speed of the stopper be at 1.5 revolutions per second? (d) Based on your answer in part (c). calculate the centripetal force acting on the stopper. (e) Generally, will the centripetal force you calculated in part (d) be equal to the net force you showed graphically in part (b)? Why or why not? Briefly explain your