II$.$d$.$ In the figure shown below, two wedge blocks are used to hold the specimen in a tension testing machine. The coefficients of static friction are ${}_A=0\mathrm{.}1$ at A and ${}_B=0\mathrm{.}5$ at B $.$ Neglect the weight of the blocks. Consider the situation that all contact surfaces have impending motion, and the specimen will not slip regardless of the applied load $($self$-$locking$).$

Draw the free body diagrams of $1)$ the wedge, and $2)$ the specimen.

What is the normal force between the wedge and specimen? $($a$)\frac{P}{2},$

$($b$)P=($c$)2P,$

$($d$)4P,$

$($e$)5P.$

What is the design angle $$ for this self$-$locking situation?

$($Hint: try to eliminate $P$ and solve for $.)$

$($a$)1,$

$($b$)11,$

$($c$)21,$

$($d$)31,$

$($e$)41.$