Five equal charges Q=2 C are equally spaced on a semicircle of radius R=8 cm as shown in the Figure. Calculate the force on a charge q=9 C located at the center of the semicircle. (Your result must be in multiples of 1013 Newtons. That means if you get a result of a 9.2 x 1013 just type 9.2 in the answer box. Include 1 digit after the decimal point and maximum of 5% of error is accepted in your answer. Take k=9x109. )

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?