$A$ 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:

Consider a thin square plate floating on a viscous liquid in a large tank. The height $h$ of the liquid in the tank is much less than the width of the tank. The floating plate is pulled horizontally with a constant velocity $u_0$. Which of the following statements is (are) true?
$(A)$ The resistive force of liquid on the plate is inversely proportional to $h$
$(B)$ The resistive force of liquid on the plate is independent of the area of the plate
$(C)$ The tangential (shear) stress on the floor of the tank increases with $u_0$
$(D)$ The tangential (shear) stress on the plate varies linearly with the viscosity $\eta$ of the liquid

$A$ square plate of side $0.1 \, m$ moves over another plate with a velocity of $0.1 \, m/s$ in a liquid of viscosity $0.01 \, poise$. If the viscous force acting is $0.002 \, N$,what is the distance between the two plates (in $, m$)?

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 $cm/s$)?

Discuss the coefficient of viscosity in terms of stress and strain.

The coefficient of viscosity for hot air is