Meriam, Kraige & Bolton — Plane Kinetics of Rigid Bodies: Problem 6_151

6/151 The base $B$ has a mass of $5\text{ kg}$ and a radius of gyration of $80\text{ mm}$ about the central vertical axis shown. Each plate $P$ has a mass of $3\text{ kg}$. If the system is freely rotating about the vertical axis with an angular speed $N_1 = 10\text{ rev/min}$ with the plates in the vertical position, estimate the angular speed $N_2$ when the plates have moved to the horizontal positions indicated. Neglect friction.