Question $7$

The chandelier is supported by three chains which are concurrent at point $O$ as shows in

Figure $7.$ The force in each chain has a magnitude of $60$lb$.$

Figure $7$

a$)$ Express each force as a Cartesian vector

b$)$ Determine the resultant force

c$)$ Measure the coordinate direction angles of $,$ and $$

d$)$ If the resultant force at $O,$ has a magnitude of $130lb$ and is directed along the negative

$z-$axis. Determine the force in each chain.