Question

Bats chirp at high frequencies humans cannot hear. They use the echos to detect small objects, such as insects, as small as one wavelength. If a bat emits a chirp at a frequency of 60.0 kHz and the speed of of sound waves in the air is 340 m/s, what is the size in millimeters of the smallest insect the bat can detect.

Answer 1

The wavelenghth of a sound can be expressed by

& lambda; = v/f.

So, the size of the smallest insect the bat can detect is

& lambda; = 340[m/s]/(6.00x10^4[Hz]) = 5.7x10^(-3) m.