The 0.75-kg bob of a pendulum is fired from rest at position a. if the spring is compressed 50 mm and released, determine (a) its stiffness k so that the speed of the bob is zero when it reaches point b, (b) the stiffness k so that when the bob reaches point c the tension in the cord is zero

Balloon a has charge q, and identical mass balloon b has charge 10q. you hang them from threads near each other. choose all of the statements with which you agree. check all that apply. a. a and b exert the same magnitude forces on each other. b. the force that a exerts on b is 10 times the force that b exerts on a. c. the angle between the thread supporting a and the vertical is < the angle between the thread supporting b and the vertical. d. the force that a exerts on b is 1/10 the force that b exerts on a.