Question $1$: While removing a wheel to change a tire, a driver applies forces $P=35lb$ at the ends of two of the arms of a lug wrench. The wrench is made of steel with shear modulus of elasticity $G=10\mathrm{.}5{10}^3$ksi. Each arm of the wrench is $9\mathrm{.}0$ in $.$ long and has a solid circular cross section of diameter $d=\frac{5}{8}$ in$.$

a$)$ Determine the maximum shear stress in the arm that is turning the lug nut $($arm A$).$

b$)$ Determine the angle of twist $($in degrees$)$ of this same arm.