Question

The velocity of water near the surface of river is 5 m/s whereas the depth is 5m. The coefficient of viscosity of water is ${10}^{-2}$ poise, then shearing stress will be

• A. $1N/m^2$
• B. $5\times {10}^{-3}N/m^2$
• C. ${10}^{-2}N/m^2$
• D. $2.5\times {10}^{-3}N/m^2$

Answer 1

The correct option is C ${10}^{-2}N/m^2$

$\frac{F}{A}=-\eta \frac{dv}{dx}={10}^{-2}\times \frac{5}{5}={10}^{-2}N/m^2$