Estimate the number of raindrops that fell during the storm

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To estimate the number of raindrops that fell during the storm, one must first determine the volume of rain that fell over the specified area. The storm dropped half an inch of rain, covering approximately 10^8 m^2, resulting in a total volume of about 1 million cubic meters. The average volume of a raindrop is needed for the calculation, which is often approximated to be around 0.05 mL or 5 x 10^-8 m^3. Using these values, the number of raindrops can be estimated by dividing the total volume of rain by the volume of a single raindrop. This problem exemplifies a Fermi problem, where approximations are essential to arrive at a rough estimate.
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Homework Statement


A thunderstorm drops half an inch of rain (approximately .01m) of rain which covers an area of about 70 miles (approximately 10^8 m^2).Estimate the number of raindrops that fell during the storm.


Homework Equations


Area of a sphere,the raindrop= (4/3)(pi)(r^3)


The Attempt at a Solution


no idea where to start because the radius and area of a single raindrop is unknown
 
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Nothing else is given?
 
nope
 
Maybe google average volume of a rain drop, can't do this problem without more info. Unless they want you to estimate the size of a raindrop, or have a previous problem that tells you.
 
that's a fermi problem; they give these like problems in the beginning,
so just use approximations,
there's no correct answer
 
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