There is a $1$ $mm$ thick layer of glycerine between a flat plate of area $100$ $cm^2$ and a big fixed plate. If the coefficient of viscosity of glycerine is $1.0$ $kg/(m \cdot s)$,then what force in $N$ is required to move the plate with a velocity of $7$ $cm/s$?

$A$ 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:

What is viscosity? What is the cause of it?

When the temperature increases,the viscosity of

$A$ cylindrical metal box whose flat surface has an area of $0.01 \ m^2$ rests on a liquid layer of $0.3 \ mm$ thickness. If upon applying a horizontal force of magnitude $\frac{1}{3} \ N$,the box slides with a constant speed of $0.09 \ m/s$,the coefficient of viscosity of the liquid is nearly:

Write one practical use of viscosity.