50. A narrow beam of ultrasonic waves with a frequency ν0 = 50 kHz is directed from the fixed locator for the approaching submarine. U determine the speed of the submarine, when the beat frequency ν1 (source oscillation frequency difference and the signal reflected from the boat) is equal to 250 Hz. Speed υ ultrasound in seawater taken equal to 1.5 km / s.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)