Question

The pressure drop in a 30 cm diameter horizontal pipe is 60 kPa in a distance of 15 m. The wall shear stress is kPa is

• A. 0.1
• B. 0.2
• C. 0.3
• D. 0.4

Answer 1

The correct option is C 0.3

$\text{The wall shear stress,}\tau ,\text{is given by}$

$\tau =-\left(\frac{\partial P}{\partial x}\right)\frac{R}{2}$

$\tau =-\left(\frac{-60}{15}\right)\times \frac{15}{100\times 2}$

$\tau =0.3\text{kPa}$