Question

Question: A diver underwater sees a dolphin swimming towards him with a speed of 7.257 m/s. The diver gets excited and swims towards the dolphin with a speed of 11.994 m/s. The dolphin sees the diver and emits a call with a frequency of 22.73 kHz. Assume that the speed of sound through the water is 1521 m/s. Part 1) What frequency does the diver detect coming from the dolphin? f= kHz Part 2) The sound is reflected off the diver back to the dolphin. What frequency does the dolphin detect? f KH Part 3) Suppose now that there is a strong current with a speed of 1.479 m/s in the same direction as the dolphin. What is the new frequency the dolphin detects? (Give your answer to 4 significant figures). f= kHz Check

Answer 1

KHZ 1521 – 7:257 Given that, Use speed of source Idolphin) = 7,257 m/s vor Speed of observer (divere) - 11.994 ms Original frequency € - 22:73 KHZ v speed of sound in water = 1521 m/s Part 1 According to dopplers effect, when they Observed frequency f'= f /V+Vo v-us Hence, f's (2273) / 1521 +11:994 = (22:73)/ 1532.994 1513.743 f' = 23.02 KHZ Therefore, frequency detected diver coming from the dolphin = 23.02 kHY (Answer) Part 2 Now this frequency f'is veflected back to dolphin Hence, now the service is diver (vous) and the observer is dolphin ( ug) observed frequency by delphin, f"=f"/vtv. v-vi f" = f'(v + Us - (23:02). /152177-257 1521-11.994 73) / 1 by v-va f" =_23:02 (1.013) = 23:314 kHz

Frequency Therefore, detected by dolphin 23.314 KHZ (Answer) in fown significant figures, f"= 23:31 KHZ Part3 of dolphin speed of current = 1.479 m/s in direction Therefore, velocity of dolphin = 47.257+ 1.479) v = 8.736 mis Proceeding as in part 2 y = Us = 8.736 m/s Us' = Vo = 11.994 m/s f'=23.02 kHz f new flutus vevo (23.02) (152 +8:736 (1521-111994 f'new = 23.34 kHz - New Frequency detected by dolphin = 23:34% (Answer