You perform a double‑slit experiment in order to measure the wavelength of the new laser that you received for your birthday. You set your slit spacing at 1.15 mm and place your screen 9.39 m from the slits. Then, you illuminate the slits with your new toy and find on the screen that the tenth bright fringe is 4.55 cm away from the central bright fringe (counted as the zeroth bright fringe). What is your laser's wavelength expressed in nanometers?

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?