a SINGLE minnow has no effect -- however, schools of minnows can have a conglomerated effect which _is_ significant. Other temporary environmental factors can also interfere -- entrained air in the water column (air bubbles), sea creatures that contain gaseous air in their bodies (i.e. "popping" shrimp).
The frequencies used underwater (10s of kHz) and the speed of sound (~1500 m/s) mean that the wavelengths of most sound waves (lambda = f/c, 15 kHz wave has length of 1.5 meters) compared to average fish sizes are much greater than 1.0... Sound waves of whose length is much greater than the characteristic length of an object in its path will just pass by the object instead of being reflected.... In short, minnows have NO effect...
Your calculation implies that she would be steadily accelerating along her entire fall to earth, resulting in a velocity at impact of approx. 21,000 miles per hour. In reality, she would reach her top speed of Mach 1.5 in a very short amount of time (a few seconds). If you assume that she spends the majority of her free-fall from 31 miles at about 900 miles per hour (nice round number greater than the speed of sound), then she will fall for about 124 seconds...
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Let me clarify:
a SINGLE minnow has no effect -- however, schools of minnows can have a conglomerated effect which _is_ significant. Other temporary environmental factors can also interfere -- entrained air in the water column (air bubbles), sea creatures that contain gaseous air in their bodies (i.e. "popping" shrimp).
The frequencies used underwater (10s of kHz) and the speed of sound (~1500 m/s) mean that the wavelengths of most sound waves (lambda = f/c, 15 kHz wave has length of 1.5 meters) compared to average fish sizes are much greater than 1.0... Sound waves of whose length is much greater than the characteristic length of an object in its path will just pass by the object instead of being reflected.... In short, minnows have NO effect...
Your calculation implies that she would be steadily accelerating along her entire fall to earth, resulting in a velocity at impact of approx. 21,000 miles per hour. In reality, she would reach her top speed of Mach 1.5 in a very short amount of time (a few seconds). If you assume that she spends the majority of her free-fall from 31 miles at about 900 miles per hour (nice round number greater than the speed of sound), then she will fall for about 124 seconds...