1) At an air show, a girl is standing by a 250 m tower and notices the flag on top suddenly waving. Then, 0.55 s later, she is startled by an unexpected sonic boom. At what Mach number must the jet have been flying judging by the time delay between the two events?
2) The random noise level of a buzzing mosquito is 32dB and that heard in a typical classroom is 71dB. How many mosquitos are required to make a noise level equivalent to that heard ina typical classroom?