A Lincoln Continental is twice as long as a VW Beetle, when they are at rest. On a 2-lane road, the Continental driver passes the VW Beetle. Unfortunately for the Continental driver, a stationary policeman has set up a speed trap, and the policeman observes that the Continental and the Beetle have the same length. The VW is going at half the speed of light. How fast is the Lincoln going ? (Express your answer as a multiple of c).

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?