• # question_answer The equation of free vibrations of a system is $\ddot{x}+36\,\,{{\pi }^{2}}X=0.$ Its natural frequency is: A) $46\text{ }Hz$             B) $3\,\,\pi Hz$C) $3\text{ }Hz$               D) $6\,\pi Hz$

${{f}_{n}}=\frac{1}{2\pi }\sqrt{36{{\pi }^{2}}}=3Hz$