Four particles with masses 7 kg, 6 kg, 2 kg,and 5 kg are connected by rigid rods of nelgigible mass as shown. The origin is centered on the mass in the lower-left corner. The rectangle is 8 m wide and 5 m long. If the system rotates in the xy plane about the z axis (origin, O) with an angular speed of 5 rad/s.
1. Calculate the moment of inertia of the system about the z axis.
2. Find the rotational energy of the system.