Question I found on the AAMC website

[lamborghiniMD]

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Hey so I found this question on the MCAT 2015 Guide. How do I even solve this?

The radius of the aorta is about 1.0 cm and blood passes through it at a velocity of 30 cm/s. A typical capillary has a radius of about 4 × 10–4 cm with blood passing through at a velocity of 5 × 10–4 m/s. Using this data, what is the approximate number of capillaries in a human body?




The answer is 4 x 10^9

 

[LoLCareerGoals]

(1cm/0.0004cm)^2 x (30/0.05) = 3,750,000,000. Basically try to think of as volume per second.
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