Statics Questions

A body weighing $13\text{kg}$ is suspended by two strings $5\text{m}$ and $12\text{m}$ long, their other ends being fastened to the extremities of a rod $13\text{m}$ long. If the rod be so held that the body hangs immediately below the middle point. The tensions in the strings are:

The resultant of two forces $P\text{N}$ and $3\text{N}$ is a force of $7\text{N}$. If the direction of $3\text{N}$ force were reversed, the resultant would be $\sqrt{19}\text{N}$. The value of $P$ is: