The speed of the water in a river is $V$ near the surface. If the coefficient of viscosity of water is $\eta$ and the depth of the river is $H$,then the shearing stress between the horizontal layers of water is

Water is flowing steadily in a river. $A$ and $B$ are two layers of water at heights $40 \ cm$ and $90 \ cm$ from the bottom. The velocity of layer $A$ is $12 \ cm/s$. If the velocity of the water at the bottom is $0$,what is the velocity of layer $B$ (in $cm/s$)?

Define velocity gradient and give its unit. Also,write the dimensional formula of the velocity gradient.

$A$ space $2.5\ cm$ wide between two large plane surfaces is filled with oil. The force required to drag a very thin plate of area $0.5\ m^2$ just midway between the surfaces at a speed of $0.5\ m/s$ is $1\ N$. The coefficient of viscosity in $kg/(m \cdot s)$ is:

Viscosity is the property of a liquid due to which it :

$A$ metal block of base area $0.2\; m^{2}$ is connected to a $0.02\; kg$ mass via a string that passes over an ideal pulley as shown in the figure. $A$ liquid film of thickness $0.6\; mm$ is placed between the block and the table. When released,the block moves to the right with a constant speed of $0.17\; m/s$. The coefficient of viscosity of the liquid is: