$1\mathrm{.}6\mathrm{.}23$ A $10-kg$ block slides down a smooth inclined surface

as shown in Fig. P$1\mathrm{.}6\mathrm{.}23.$ Determine the terminal velocity of

the block if the $0\mathrm{.}1-mm$ gap between the block and the surface

contains SAE $30$ oil at $15\mathrm{.}5C.$ Assume the velocity distribution

in the gap is linear, and the area of the block in contact with the

oil is $0\mathrm{.}1m^2.$