Physics CAPA Problem..Please help!?
Blood flows in an aorta of radius 4.00mm at 25.0cm/s. Calculate the volume flow rate.
Although the cross-sectional area of a capillary is much smaller than that of the aorta, there are many capillaries, so their total cross-sectional area is much larger. If all the blood from the aorta flows into the capillaries and the speed of flow through the capillaries is 1.05mm/s, calculate the total cross-sectional area of the capillaries.
Comments
It is a bit like calculating the volume of a cylinder.
The cross-sectional area is π * r²
A = 3.14 * (0.4cm)² = 0.504 cm²
In one second, the flow moves 25 cm
so the volume per second is 0.504 * 25 = 12.60 cm³/sec
In capillaries, speed = 1.05 mm/s = 0.105 cm/s
Volumetric flow rate / speed gives cross-sectional area:
12.60 / 0.105 = 120 cm²
Double check all this because I already found I had made one mistake.