$10-26$ A $50-cm30-cm20-cm$ block weighing $150N$ is to

be moved at a constant velocity of $0\mathrm{.}8\frac{m}{s}$ on an inclined sur$-$

face with a friction coefficient of $0\mathrm{.}27.($a$)$ Determine the force

$F$ that needs to be applied in the horizontal direction. $($b$)$ If a

$0\mathrm{.}40-$mm$-$thick oil film with a dynamic viscosity of $0\mathrm{.}012Pa*s$

is applied between the block and inclined surface, determine the

percent reduction in the required force.