Given: Block A weighs $50N$ and block B weighs $25N.$

Let $s=0\mathrm{.}3$ and $k=0\mathrm{.}2$ between all of the surfaces.

Find: $,$ a$.$ The smallest force $P$ required to start block $B$ if block $A$ is restrained by cable $C$

b$.$ The smallest force $P$ required to start block $B$ if cable $C$ is removed.