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.
Given: The frequency of ultrasonic sound emitted by the bat is 1000 kHz , the speed of the sound in air is 340 m / s and the speed of the sound in water is 1486 m / s .
(a)
The wavelength of the reflected sound is given as,
λ a = v a v
Where, v a is the speed of the sound in air and v is the frequency of ultrasonic sound emitted by the bat.
By substituting the given values in the above equation, we get
λ a = 340 1000 × 10 3 Hz = 3.40 × 10 − 4 m
Thus, the wavelength of the reflected sound is 3.40 × 10 − 4 m .
(b)
The wavelength of the transmitted sound is given as,
λ w = v w v
where, v w is the speed of the sound in water and v is the frequency of ultrasonic sound emitted by the bat.
By substituting the given values in the above equation, we get
λ w = 1486 1000 × 10 3 Hz = 1.49 × 10 − 3 m
Thus, the wavelength of the transmitted sound is 1.49 × 10 − 3 m .
Given: The frequency of ultrasonic sound emitted by the bat is
(a)
The wavelength of the reflected sound is given as,
Where,
By substituting the given values in the above equation, we get
Thus, the wavelength of the reflected sound is
(b)
The wavelength of the transmitted sound is given as,
where,
By substituting the given values in the above equation, we get
Thus, the wavelength of the transmitted sound is
