$A$ good lubricant should have

$A$ metal plate of area $10^{-2} \,m^2$ rests on a layer of castor oil,$2 \times 10^{-3} \,m$ thick,whose coefficient of viscosity is $1.55 \,Ns\, m^{-2}$. The approximate horizontal force required to move the plate with a uniform speed of $3 \times 10^{-2} \,ms^{-1}$ is (in $N$)

Why do machine parts become sticky in winter?

$A$ flat plate of area $10 \, cm^2$ is separated from a large plate by a layer of glycerine $1 \, mm$ thick. If the coefficient of viscosity of glycerine is $20 \, \text{poise}$, the force required to keep the plate moving with a velocity of $1 \, cm/s$ is .......... $dyne$.

How does the coefficient of viscosity of a liquid and a gas depend on temperature?

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.