Poiseuille's Law describes the flow rate of fluids in a cylindrical tube which has applications in engineering and medicine. The relation is F = piP over 8nL times r^4 where F is the fluid flow rate (liters/minute) and is the radius of the cylinder (in millimeters), P is the fluid pressure, n is viscosity, and L is the cylinder's length. In the following examples, we consider P, n and L to remain constant, while r is varied. 7. Suppose that exercise increases the radius of an artery by 10%. What is the corresponding percentage increase in blood flow rate through the artery?
8. If a medication causes a 15% increase in the radius of an artery, what corresponding percentage increase in blood flow rate is expected?
9. If cholesterol decreases the radius of an artery by 20%, what is the corresponding decrease in
the blood flow rate through the artery?