Q. A bat flying at 4.80 m/s is chasing an insect flying in the same direction. If the bat emits a 40.0-kHz chirp and receives back an echo at 40.4 kHz, what is the speed of the insect? (Take the speed of sound in air to be 340 m/s.)
Q. A nonreflective coating (n = 1.40) covers the glass (n = 1.52) of a camera lens. Assuming that the coating prevents reflection of a specific wavelength (vacuum = 535 nm), determine the minimum nonzero thickness that the coating can have.