Question

find the pressure gradient of a capillary tube with radius 0.514*10^-3 m when volume of water flowing through it is 7.06 cm^3 per min. coeff of viscosity=0.00138 Pa *s

Answer 1

Answer:

5923.7 Pa/m

Explanation:

radius of capillary tube, r = 0.514 x 10^-3 m

Volume of flow, V = 7.06 cm^3/min = 1.176 x 10^-7 m^3/s

viscosity, η = 0.00138 Pa s

By use of Poiseuillie's law

$V = \frac{\pi P\timesr^{4}}{8\eta\times l}$

Where, V be the volume flow per second and l be the length of the tube

So, pressure gradient

$\frac{P}{l} = \frac{8\eta V}}{\pi r^{4}}$

$\frac{P}{l} = \frac{8 \times 0.00138 \times 1.176 \times 10^-7}}{3.14 \times 0.514^{4} \times 10^{-12}}$

P/l = 5923.7 Pa/m