1. The problem statement, all variables and given/known data The aorta carries blood away from the heart at a speed of about 40 cm/s and has a radius of approx. 1.1cm. The aorta branches eventually into a large number of tiny capillaries that distribute the blood to the various body organs. In a capillary, the blood speed is approx. 0.07 cm/s, and the radius is about 6 x 10 -4 cm. Treat the blood as an incompressible flulid and use these data to determine the approx number of capillaries in the human body. 2. Relevant equations I think: A1 x V1 = A2 x V2 and A = pi (r)^2 A = cross sectional area of tube V= velocity 3. The attempt at a solution I have figured out the areas of the cross sections of the capillary and the aorta. I have labeled them: Ac and Aa respectively. Ac= 1.13097 x 10^-6 cm^2 Aa= 3.8013 cm^2 I cannot figure out where to go with this information. It seems like I need to know a volume or a length of some sort. Can anybody help me out please? Thanks!