- #1

oddjobmj

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## Homework Statement

High blood pressure results from constriction of arteries. To maintain a normal flow rate (flux), the heart has to pump harder, thus increasing the blood pressure. Use Poiseille's Law to show that if R

_{0}and P

_{0}are normal value sof the radius and pressure in an artery and the constricted values are R and P, then for the flux to remain constant, P and R are related by the equation

P/P

_{0}= (R

_{0}/R)^4

Deduce that if the radius of an artery is reduced to three-fourths of its former value, then the pressure is more than tripled.

## Homework Equations

P/P

_{0}= (R

_{0}/R)^4

and what I know of Poiseille's Law

F = ((pi)(P)(R^4))/((8)(n)(l))

Where R=volume, P=pressure, l=length of blood vessel, F=flux, and n=viscosity of blood

## The Attempt at a Solution

Firstly, I've worded and formatted the question exactly as listed. I did this because I'm a little confused at what it's even asking me to do. Does it read like there are two parts; 1) Proving P and R are related by the given equation and 2) deducing the given specific relationship between a change in radius and a change in volume?

I really don't know where to start. I don't want the answer given to me but any hints on how to get started and what they're really asking me for would be greatly appreciated.