Aboy flying a kite is standing 30 ft from a point directly under the kite. if the string to the kite is 50 ft long, what is the angle of elevation of the kite (the angle between the ground where the boy is standing and the kite string)?

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?