Underwater illusion. One clue used by your brain to determine the direction of a

Question

Underwater illusion. One clue used by your brain to determine the direction of a source of sound is the time delay t between the arrival of the sound at the ear closer to the source and the arrival at the farther ear. Assume that the source is distant so that a wavefront from it is approximately planar when it reaches you, and let D = 0.219 m represent the separation between your ears. (a) If the source is located at angle = 31.0o in front of you (the figure) and the air temperature is 20oC, what is t? (b) If you are submerged in water and the sound source is directly to your right, what is t? (c) Based on the time-delay clue, your brain interprets the submerged sound to arrive at an angle from the forward direction. Evaluate for fresh water at 20oC. Assume the speed of sound v in air at 20oC = 343 m/s and the speed of sound vw in water at 20oC = 1482 m/s.

Explanation / Answer

the time delay is due to the del t is due to distnace d that each wavefront must travel to reach our left ear after it reaches the right ear

a) del t = d/v = Dsin theta /v = 0.219 *sin 31 / 343 = 0.000328 s

b) del t in water = D sin theta /Vw

= 0.219*sin 90 / 1482 = 0.000147 s

c) apparent angle = sin^-1 ( V/Vw) = sin^-1 ( 343/1482 ) = 13.382 o

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.