The buildup of plaque on the walls of an artery may decrease its diameter from 1.1 cm to 0.90 cm. The speed of blood flow was 17 cm/s before reaching the region of plaque buildup. Fid the speed of blood flow within the plaque region. (i found the speed to be 25 cm/s and its correct)
Find the pressure drop within the plaque region.
(i tried using the formula delta P = 1/2*rho*(V2^2 - V1^2) i got 17.8 Pa but its not right)
What am i doing wrong ?

Question

The buildup of plaque on the walls of an artery may decrease its diameter from 1.1 cm to 0.90 cm. The speed of blood flow was 17 cm/s before reaching the region of plaque buildup. Fid the speed of blood flow within the plaque region. (i found the speed to be 25 cm/s and its correct)
Find the pressure drop within the plaque region.
(i tried using the formula delta P = 1/2*rho*(V2^2 - V1^2) i got 17.8 Pa but its not right)
What am i doing wrong ?

shayaan_mustafa · Answer

Hello.

You used the formula,
$$q=0.5*\rho*\upsilon ^{2}$$
what did you use in place of $$\rho?$$

And it is the formula of "Dynamic Pressure" and it is indicated by "q"
$$\rho$$ is the density.

Show your calculations.

anonymous · Answer

i said (1/2)(1000)(.254^2 - .17^2)=17.8

shayaan_mustafa · Answer

my answer is 16.8Pa.

well method is correct.