Problem on Doppler's Effect Two dolphins are following a submarine that is traveling at 15m/s (see picture below). While dolphin #1 is swimming at a speed of 10m/s towards the submarine, dolphin #2 suddenly stops. Dolphin #1 emits a call of 40,000Hz. (Sound travels at about 1500 m/s in water.) V Dolphin # 1 Dolphin #1 V sub Dolphin #2 (at rest) a) What is the frequency of the sound heard by dolphin #2? b) On the back of the submarine there is an ultrasonic detector used to capture dolphin's calls for the study of dolphin's language. What is the frequency of the sound emitted by dolphin #1 as it is recorded by the detector? c) If the sound emitted by dolphin #1 reaches the submarine and is reflected back, what is the frequency of the sound heard by dolphin #2? Dolphin #1 decides to turn around and dolphin #2 follows it. Both swim at 5m/s away from the submarine, and dolphin #1 again emits a call of 40,000Hz. d) What frequency will dolphin #2 detect now? e) What is the wavelength of the sound wave in water produced by dolphin #1 and detected by dolphin #2