Pressure Difference to Make Blood Flow Thru Artery

AI Thread Summary
To calculate the pressure difference required for blood flow through an artery with a radius of 2.0 mm and length of 0.18 m at a speed of 5.6 cm/s, the viscosity of blood is a critical factor, typically ranging from 3e-3 to 4e-3 Pa·s. The initial calculation yielded a pressure difference of 80.64 Pa, but this was flagged as incorrect, prompting a request for assistance. The user suspects that the choice of viscosity may be the source of the error, as different sources provide varying values. Clarification on the appropriate viscosity to use and any additional variables affecting the calculation is sought. Accurate viscosity selection is essential for determining the correct pressure difference in this context.
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Homework Statement


What is the pressure difference required to make blood flow through an artery of inner radius 2.0 mm and length 0.18 m at a speed of 5.6 cm/s?

Homework Equations


P1-P2 = Q8nL/pi*r fourth
or P1-P2 = velocity*8*viscosity of blood*L/rsquared
viscosity of blood = 4 x 10e-3
r = 2.0 mm = 2 x 10e-3 m
l = .18 m

The Attempt at a Solution


P1-P2 = .056*8*4x10e-3*.18/(2x10e-3)(2x10e-3)
P1- P2 = .322 x 10e-3/4 x 10e-6 = .08064 x 10e3 = 80.64 Pa

This is wrong when I submit it? HELP asap?

I read that whole blood viscosity at 37 degrees celsius is from 3e-3 to 4e-3; in one book it says 2.1e-3? What do I use as I suspect that is what caused my error?
 
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dvolpe said:

Homework Statement


What is the pressure difference required to make blood flow through an artery of inner radius 2.0 mm and length 0.18 m at a speed of 5.6 cm/s?


Homework Equations


P1-P2 = Q8nL/pi*r fourth
or P1-P2 = velocity*8*viscosity of blood*L/rsquared
viscosity of blood = 4 x 10e-3
r = 2.0 mm = 2 x 10e-3 m
l = .18 m

The Attempt at a Solution


P1-P2 = .056*8*4x10e-3*.18/(2x10e-3)(2x10e-3)
P1- P2 = .322 x 10e-3/4 x 10e-6 = .08064 x 10e3 = 80.64 Pa

This is wrong when I submit it? HELP asap?

I read that whole blood viscosity at 37 degrees celsius is from 3e-3 to 4e-3; in one book it says 2.1e-3? What do I use as I suspect that is what caused my error?

Are there any other variables?
 

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