Water in a river $20 \ m$ deep is flowing at a speed of $10 \ ms^{-1}$. The shearing stress between the horizontal layers of water in the river in $Nm^{-2}$ is (Coefficient of viscosity of water $= 10^{-3} \ SI \ units$)

$A$ liquid having a coefficient of viscosity $0.02 \, \text{decapoise}$ is filled in a container of cross-sectional area $20 \, m^2$. If the viscous drag between two adjacent layers in flowing is $1 \, N$, then the velocity gradient is ........ $s^{-1}$.

When stirring with a spoon is stopped in milk,it comes to rest after some time. Why?

$A$ cubical block of side $a$ and density $\rho$ slides over a fixed inclined plane with constant velocity $v$. There is a thin film of viscous fluid of thickness $t$ between the plane and the block. If the angle of inclination is $37^{\circ}$,then the coefficient of viscosity of the thin film will be:

$A$ river $10\,m$ deep is flowing at $5\,m/s$. The shearing stress between horizontal layers of the river is :- $(\eta = 10^{-3}\,SI\,unit)$

$A$ metal block of base area $0.20\,m^2$ is placed on a table,as shown in the figure. $A$ liquid film of thickness $0.25\,mm$ is inserted between the block and the table. The block is pushed by a horizontal force of $0.1\,N$ and moves with a constant speed. If the viscosity of the liquid is $5.0 \times 10^{-3} \,Pa-s$,the speed of the block is $.........\times 10^{-3}\,m/s$.