One end of a straight uniform $1 m$ long bar is pivoted on horizontal table. It is released from rest when it makes an angle $30 ^ { \circ }$ from the horizontal (see figure). Its angular speed when it hits the table is given as $\sqrt { n } \mathrm { rad } s ^ { - 1 }$, where $n$ is an integer. The value of $n$ is $\_\_\_\_$