A) Time Period = (Time Taken)/ (Number of Oscillations)
= (1/500) = 0.002 sec.
(b) The frequency of the vibrations in hertz is 500 Hz. Because 1Hz = 1 vibration/second. (c) We can hear this because it is in the range of 20Hz to 20,000Hz.Read more on Sarthaks.com - https://www.sarthaks.com/821303/the-sound-from-insect-produced-when-vibrates-wings-average-rate-500-vibrations-per-second