In the Previous Problem, If the Mass Is Set in Motion

Multiple Choice

In the previous problem, if the mass is set in motion, the natural frequency, $\omega$ ,is

A) $4 \sqrt { 2 } \mathrm { sec }$
B) $4 \sqrt { 2 } \sec ^ { - 1 }$
C) $32 \mathrm { sec }$
D) $32 \mathrm { sec } ^ { - 1 }$
E) $\sec ^ { - 1 }$