Question

The vein of a person is horizontal and its length is $0.314m$. It has an internal radius of $1mm.$ The average blood flow through the vein is $5cm{s}^{-1}$. The rate of flow of blood in ${10}^{-7}{m}^3{s}^{-1}$ is :

• A. $1.57$
• B. $0.157$
• C. $15.7$
• D. $0.0157$

Answer 1

Answer: (A)

$1.57$

From Poisuilli's equation,
velocity of blood flow through veins$=5cm/s$
Rate of flow of blood$=\frac{5}{100}m/s\times \pi \times {\left({10}^{-3}\right)}^2$
$=\frac{5}{10}\times \pi \times {10}^{-7}{m}^3/s$

$=\frac{\pi }{2}\times {10}^{-7}{m}^3/s$

$=1.57\times {10}^{-7}{m}^3/s$