$2-(25$ pts$.)$ Find the torque on link $2$ necessary to maintain static equilibrium for the $4-$bar mechanisn shown below. Use analytical method, draw free body diagram of each link.

$O_{2}A=3\mathrm{.}5in.,AB=O_{4}B=6in.,O_{4}C=7in$

Use matrix method or use $9$ equations and $9$ unknowns method to solve problem.