A $1\mathrm{.}60-$kg object attached to a spring moves without friction $($b $=0)$ and is driven by an external force given by the expression F $=4\mathrm{.}90$sin$(2$t$),$ where F is in newtons and t is in seconds. The force constant of the spring is $17\mathrm{.}0$ N$/$m$.$

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