What is the Doppler effect? A. the shift in a wave's frequency due to relative motion between observer and source B. the increase in a wave's speed due to angle between observer and source C. the decrease in a wave's wavelength due to difference between media densities D. the shift in a wave's volume due to superposition of waveforms If the stationary submarine aims a sonar wave of frequency 256 Hz at the merchant ship and discovers it returns to the submarine at a shifted frequency of 253 Hz, what is the merchant ship's speed? (Recall the speed of sound in water to be 1498 m/s. Also, be aware Question 32 has no influence on your interpretation of the scenario described inthis question.) The speed of the merchant ship is____m/s.

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