An air-filled toroidal solenoid has a mean radius of 15.5 cm and a cross-sectional area of 4.95 cm^2. When the current is 12.5 A, the energy stored is 0.395 J. How many turns does the winding have?

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.