The build-up of plaque on the walls of an artery decreases its diameter from 1.1 cm to 0.60 cm. If the speed of the blood flow is 0.15 m/s before reaching the region of plaque build-up, find the speed of blood flow within the plaque region. [3 marks]

Question

The build-up of plaque on the walls of an artery decreases its diameter from 1.1 cm to 0.60 cm. If the speed of the blood flow is 0.15 m/s before reaching the region of plaque build-up, find the speed of blood flow within the plaque region.	[3 marks]

drwls · Answer

According to the continuity equation of steady state incompressible flow,
V*A = constant.

The area ratio A2/A1 = (0.6/1.1)^2
= 0.2975

That is the reciprocal of the speed ratio, V2/V1 = 3.36

Solve for V2. You know what V1 is.