Answer to Question #15263 in Acoustics for Taylor

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.