When a power of 310 watts is applied to it, a pulley lifts box a one meter. the same pulley is used to lift box b. when the same amount of power is applied to box b, it is raised two meters. what can you say about the mass of the two boxes?

a. the mass of box a is half the mass of box b.
b. the mass of box a is three times the mass of box b.
c. the mass of box a is one–third the mass of box b.
d. the mass of box a is double the mass of box b.

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?