$4\mathrm{.}93$ A small winch is used to raise a $\backslash (120-\backslash$mathrm$\{$lb$\}\backslash )$ load. Find $($a$)$ the magnitude of the vertical force $\backslash (\backslash$mathbf$\{$P$\}\backslash )$ that should be applied at $\backslash ($ C $\backslash )$ to maintain equilibrium in the position shown, $($b$)$ the reactions at $\backslash ($ A $\backslash )$ and $\backslash ($ B $\backslash ),$ assuming that the bearing at $\backslash ($ B $\backslash )$ does not exert any axial thrust.