Abook is sitting on a desk. what best describes the normal force acting on the book? a)the upward force the desk pushes on the book b)the upward force the book pulls on the earth c)the downward force the book pushes on the desk d)the downward force the earth pulls on the book

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?