A river 10 m deep is flowing at 5 ms -1. The shearing stress between horizontal layers of the river is ( η=10-3 SI units)

Question

A river 10 m deep is flowing at 5 ms -1. The shearing stress between horizontal layers of the river is ( η=10-3 SI units) (A) 10-3 N / m 2 (B) 0.8 × 10-3 N / m 2 (C) 0.5 × 10-3 N / m 2 (D) 1 N / m 2

Tardigrade Admin · Accepted Answer

Shearing stress =( mid text viscous force mid/ text area ) =(η A (d v/d x)/A)=η (d v/d x) =10-3 × (5/10) N / m 2=0.5 × 10-3 N / m 2

Q. A river $10 m$ deep is flowing at $5 m s^{- 1}$ . The shearing stress between horizontal layers of the river is ( $η = 1 0^{- 3} S I$ units)

$1 0^{- 3} N / m^{2}$

$0.8 \times 1 0^{- 3} N / m^{2}$

$0.5 \times 1 0^{- 3} N / m^{2}$

$1 N / m^{2}$

Shearing stress $= \frac{∣ viscous force ∣}{area}$
$= \frac{η A \frac{d v}{d x}}{A} = η \frac{d v}{d x}$
$= 1 0^{- 3} \times \frac{5}{10} N / m^{2} = 0.5 \times 1 0^{- 3} N / m^{2}$

Q. A river 10m deep is flowing at 5ms−1. The shearing stress between horizontal layers of the river is ( η=10−3SI units)

10−3N/m2

0.8×10−3N/m2

0.5×10−3N/m2

1N/m2