The aorta pumps blood away from the heart at about 40 cm/s and has a radius of about 1.0 cm. It then branches into many capillar
ies, each with a radius of about 5×10−4 cm carrying blood at a speed of 0.10 cm/s. How many capillaries are there? a. 1.6×109
b. 16
c. 8.0×105
d. 1.6×105