Problem $3$: A crank is subjected to two couple forces. Determine the magnitude of the couple force vec$(F)$ so that the resultant couple moment on the crank is zero. Hint: Try finding the components of the forces along and perpendicular to the crank.

$3\mathrm{.}1)$ Determine the magnitude and direction of the moment about A due to the $200$ lb couple force.

$3\mathrm{.}2)$ Determine the magnitude of the couple force vec$(F)$ so that the resultant moment about $A$ is zero.