Question

At night, bats emit pulses of sound to detect obstacles and prey. The speed of sound in air is 340 m/s. The pulse of sound hits a stationary object and is reflected back to the bat. The pulse is received by the bat 0.12s after it was emitted. Calculate the distance travelled by the pulse of sound during this time.

Answer 1

(a) Frequency of the ultrasonic sound, f=1000kHz=10

6

Hz

Speed of sound in air, V

a

=340m/s

The wavelength (λ r ) of the reflected sound is given by the relation:λr

=V/f

=340/10 6

=3.4×10 −4 m.

(b) Frequency of the ultrasonic sound, f=1000kHz=10

6

Hz

Speed of sound in water, V w

=1486 m/s

The wavelength of the transmitted sound is given as:lλ r

=1486/10 6 =1.49×10

−3 m.

$\huge \pink{~} \red {τ} \green {α} \blue {v} \orange {v} \pink {u} \red {♡}$

Answer 2

Final answer :

Distance travelled by the pulse is 204m