$2\mathrm{.}4$

$*2-44.$ The magnitude of the resultant force acting on the bracket is to be $400$ N $.$ Determine the magnitude of $F_1$ if ${}_3=30.$

$2-45.$ If the resultant force acting on the bracket is to be directed along the positive $u$ axis, and the magnitude of $F_1$ is required to be minimum, determine the magnitudes of the resultant force and $F_1.$

$2-46.$ If the magnitude of the resultant force acting on the bracket is $600$ N $,$ directed along the positive $u$ axis, determine the magnitude of $F$ and its direction $.$