In a young's double-slit experiment, the seventh dark fringe is located 0.028 m to the side of the central bright fringe on a flat screen, which is 1.1 m away from the slits. the separation between the slits is 1.6 × 10-4 m. what is the wavelength of the light being used?

Use: dsin(θ) = mλ  where d is slit separation, m is fringe order (7), and 
θ = tan⁻¹(0.028/1.1) = 1.458deg
Now λ = dsin(θ) /m = (1.6e-4)(sin(1.458))/7 = 5.96e-7 or λ = 596 nm  

Jet streams are relatively narrow bands of strong wind in the upper levels of the atmosphere. the winds blow from west to east in jet streams but the flow often shifts to the north and south. jet streams follow the boundaries between hot and cold air. the earth's rotation is responsible for the jet stream as well.