Question

A bat emits ultrasonic sound of frequency 1000 kHz in air. If the sound meets a water surface, what is the wavelength of (a) the reflected sound, (b) the transmitted sound? Speed of sound in air is 340 m s^–1 and in water 1486 m s^–1.

Answer 1

(a) Frequency of the ultrasonic sound, ν = 1000 kHz = 10⁶ Hz

Speed of sound in air, v_a = 340 m/s

The wavelength (λ_r) of the reflected sound is given by the relation:

(b) Frequency of the ultrasonic sound, ν = 1000 kHz = 10⁶ Hz

Speed of sound in water, v_w = 1486 m/s

The wavelength of the transmitted sound is given as:

= 1.49 × 10^–3 m