In Fig. $1\mathrm{.}8,$ if the fluid is glycerin at $20C$ and the width between plates is $6$ mm $,$ what shear stress $($in Pa $)$ is required to move the upper plate at $5\mathrm{.}5\frac{m}{s}?$

What is the Reynolds number if $L$ is taken to be the distance between plates?

A block of weight $W$ slides down an inclined plane while lubricated by a thin film of oil, as in Fig. P$1\mathrm{.}45.$ The film contact area is A and its thickness is

h$.$ Assuming a linear velocity distribution in the film, derive an expression for the "terminal" $($zero$-$acceleration$)$ velocity $V$ of the block. Find the

terminal velocity of the block if the block mass is $6kg,A=35c{m}^2,=15,$ and the film is $1-$mm$-$thick SAE $30$ oil at $20C.$