A1.50-kg ball and a 2.00-kg ball are glued together with the lighter one below the heavier one. the upper ball is attached to a vertical ideal spring of force constant and the system is vibrating vertically with amplitude 15.0 cm. the glue connect- ing the balls is old and weak, and it suddenly comes loose when the balls are at the lowest position in their motion. (a) why is the glue more likely to fail at the lowest point than at any other point in the motion? (b) find the amplitude and frequency of the vibrations after the lower ball has come loose.