InterviewSolution
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InterviewSolution
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The velocity of water in river is 180 km `h^(-1)` near the surface .If the river is 5 m deep,then the shearing stress between the surface layer and the bottom layer is ( cofficient of viscosity of water `eta =10^(-3)` Pa s)A. `10^(-2)N m^(-2)`B. `10^(-3)N m^(-2)`C. `10^(-4)N m^(-2)`D. `10^(-5)N m^(-2)` |
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Answer» Correct Answer - B As the velocity of water at the bottom of the river is zero, `dv=18 km h^(-1)=18xx(5)/(18)=5 m s^(-1)` Also , `dx=5 m, eta=10^(-3)` Pa s Force of viscosity , `F=etaA(dv)/(dx)` `therefore` Shearing stress, `=(F)/(A)=eta(dv)/(dx)` `=(10^(-3)xx5)/(5)=10^(-3) N m^(-2)` |
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