Math Help Forum: Poiseuille's law!

Biologists have found that the speed of blood in an artery is a function of the distance of the blood from the artery's central axis. According to Poiseuille's law, the speed of blood that is r cm from the central acis of an artery is given by the function:
S(r)= C * (R^2 -r^2)
where C is a constant and R is the radius of the artery. Suppose that for a certain artery, C= 1.76 * 10^5 cm/sec and R = 1.2 * 10^-2 cm.

a. computer the speed of the blood at the central axis of this artery.
b. computer the speed of the blood midway between the artery's wall and central axis.


please help i'm so lost

That's a lovely algebra problem. Where's the Calculus?

"at the central axis" means r = 0

"midway" means r = R/2

Plug'n'chug.

I really stink at word problems. Do you have any tricks to solve these problems better?
If you just told me to do so flat out I would obviously know how to do this!
How embarrassing
Thank you.

Originally Posted by habibixox

I really stink at word problems. Do you have any tricks to solve these problems better?
If you just told me to do so flat out I would obviously know how to do this!
How embarrassing
Thank you.

Interpret the questions in terms of the notation given, if no notation given invent some.

TKH has already told you:

For (a) r=0

For (b) r=R/2

Now you just plug the given information into the right hand side of the formula for speed.

CB