Physics

Problem

Which of the following correctly defines ultrasound? a) Sound waves with frequency greater than

2\,\text{kHz}

b) Sound waves with frequency between

20\,\text{Hz}

and

20\,\text{kHz}

c) Sound waves with frequency greater than

20\,\text{kHz}

d) Sound waves with wavelength shorter than

17\,\text{cm}

in air