When the temperature increases,the viscosity of

Write one practical use of viscosity.

The coefficient of viscosity for hot air is

The velocity of the upper layer of water in a river is $36 \, km/h$. The shearing stress between horizontal layers of water is $10^{-3} \, N/m^2$. The depth of the river is $h$. (The coefficient of viscosity of water is $10^{-2} \, Pa \cdot s$). Find the value of $h$ in meters.

The coefficient of viscosity of an ideal fluid is

$A$ flat plate of area $0.1 \,m^2$ is placed on a flat surface and is separated from it by a film of oil $10^{-5} \,m$ thick whose coefficient of viscosity is $1.5 \,N \cdot s \cdot m^{-2}$. The force required to cause the plate to slide on the surface at a constant speed of $1 \,mm \cdot s^{-1}$ is ............ $N$.