Answer
The angular speed is $~~3.6~rev/s$
Work Step by Step
We can use conservation of angular momentum to find the new angular speed:
$L_f = L_i$
$I_f~\omega_f = I_i~\omega_i$
$\omega_f = \frac{I_i~\omega_i}{I_f}$
$\omega_f = \frac{(6.0~kg~m^2)(1.2~rev/s)}{2.0~kg~m^2}$
$\omega_f = 3.6~rev/s$
The angular speed is $~~3.6~rev/s$.
