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here are two carotid arteries that feed blood to the brain, one on each side of

ID: 2002443 • Letter: H

Question

here are two carotid arteries that feed blood to the brain, one on each side of the neck and head. One patient's carotid arteries are each 11.2 cm long and have an inside diameter of 5.3 mm . Near the middle of the left artery, however, is a 2.0-cm-long stenosis, a section of the artery with a smaller diameter of 3.5 mm .

For the same blood flow rate, what is the ratio of the pressure drop along the patient's left carotid artery to the drop along his right artery?

Express your answer using two significant figures.

Problem 13.64 There are two carotid arteries that feed blood to the brain, one on each side of the neck and head. One patient's carotid arteries are each 11.2 cm long and have an inside diameter of 5.3 mm . Near the middle of the left artery, however, is a 2.0-cm-long stenosis, a section of the artery with a smaller diameter of 3.5 mm Part A For the same blood flow rate, what is the ratio of the pressure drop along the patient's left carotid artery to the drop along his right artery? Express your answer using two significant figures. A2p Apr Submit My Answers Give Up Incorrect; Try Again; 2 attempts remaining

Explanation / Answer

As this is near the middle i.e. at h = 11.2/2 =5.6 cm, and
that the density of blood is 1060 kg/m³.

right artery:
p = gh = 1060kg/m³ * 9.8m/s² * -0.056m = -582 Pa

left artery:
p' = ½(v² - v'²) + gh
v' = v(5.3/3.5)² = 2.293v
p' = ½ * 1060kg/m³ * v²(1 - 2.293²) - 582Pa
p' = -2256.80kg/m³ * v² - 582Pa

the pressure drop due to elevation.

p' / p 2.293² / 1² = 5.257 : 1 ratio of left drop to right drop ignoring head