A gear inside the clutch of a car is rotating at 4000. rpm. If the gear is in the shape of a solid disc with a diameter
of 30.00 cm and a mass of 1.125 kg, what is the kinetic energy of the gear?

Ametal ring 4.20 cm in diameter is placed between the north and south poles of large magnets with the plane of its area perpendicular to the magnetic field. these magnets produce an initial uniform field of 1.12 t between them but are gradually pulled apart, causing this field to remain uniform but decrease steadily at 0.240 t/s . (a) what is the magnitude of the electric field induced in the ring? (b) in which direction (clockwise or counterclockwise) does the current flow as viewed by someone on the south pole of the magnet?