A $2\mathrm{.}30-$kg object attached to a spring moves without friction $($b $=0)$ and is driven by an external force given by the expression F $=4\mathrm{.}80$sin$(2$t$),$ where F is in newtons and t is in seconds. The force constant of the spring is $38\mathrm{.}0$ N$/$m$.$

$($a$)$ Find the resonance angular frequency of the system.

s$-1$