4. a spherical shell with outer radius b surrounds a charge-free cavity of radius a < b. if the shell contains a charge density given by   0 3 2 c/m for 0 elsewhere v v arb r r           a. find the electric field e in all regions b. determine the electric potential v in all regions c. determine the electrostatic energy stored for r  a, a  r  b, and r  b.

Acatapult is tested by roman legionnaires. they tabulate the results in a papyrus and 2000 years later the archaeological team reads (distances translated into modern units): range = 0.4 km; angle of launch = π/5 rad; landing height = launch height. what is the initial velocity of launch of the boulders if air resistance is negligible?

Explain in physical terms how a microwave oven works. what would happen when you put a conductor in the microwave oven? explain.

You want to lose weight and have been trying to decide which type of fad diet is best for you. you ask your doctor, who responds that a. fad diets are a temporary fix but generally don't have any side effects b. fad diets can be used several times a year to maintain a healthy weight c. fad diets can be risky for your health and, in the long run, do not work d. fad diets should never be used one right after the other; there should be a break between them select the best answer from the choices provided. a b c d