A factory whistle blows at a frequency of 1216 HZ. What pitch will the passengers of a car moving at 8 m/s away from the whistle hear if the speed of sound is 343 m/s.
1315 Hz
1324 Hz
1188 Hz
1117 Hz

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?