The industrial truck is used to move the solid roll of paper up the $300$ incline. If the coefficients of static and kinetic friction between the roll and the vertical barrier of the truck and between the roll and the incline are both $0\mathrm{.}40.$ compute the required tractive foree $P$ between the tires of the truck and the borizontal surface What is the direction of friction,up the inclined plain. exaplain.

Ans. $P=22\mathrm{.}1kN$