Problem $2-1$: The assembly shown in

composed of collar $P$ on rod $OA,$ and a vertical

post $BC.$ Cable $CP$ connects post $BC$ to the

collar at $P.$ The tension in cable $PC$ is known

to be $3$ lb $,$ and the distance between point $O$ and

point $P$ on the collar is $6$ inches. Determine the

angle between the cable and rodOA, as well as

the projection of the force in $PC$ on rodOA.