The sound from an insect is produced when it vibrates its wings at an average rate of 500 vibrations per second: (a) What is the time-period of the vibrations ?
(b) What is the frequency of the vibrations in hertz ?
(c) Can we hear this sound? Why or why not?

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

This is a material, medium of substance that does not conduct electrical current. Examples: Eraser, plastic and probably glass.