Two concentric spherical shells of radii a and b (a < b) carry charge densities of +q and –q, respectively. a. find the electric field e everywhere. b. determine the electric potential v everywhere. c. calculate the potential difference between the two shells, vab d. calculate the electrostatic energy stored inside the smaller shell, in between the two shells, and outside the larger shell.

Asimple speed reducer is composed of 2 spur gears. the pinion gear has a pitch diameter of 0.75" and 36 teeth while the driven gear has a pitch diameter of 4.0" and 192 teeth. a)-what is the diametral pitch of each gear? b)-if an electric motor rotating ccw at 3000 rpm is coupled to the pinion, what is the rotational speed of the driven gear? c)-if the torque delivered to the pinion is 1 n-m, what is the torque on the driven gear? d)-what is the power transmitted by the gear train?