physics question (answer is given, but idk how to do this)

Question

A wind turbine with 3 blades that rotate about their end (rod rotating about its end) spins with an angular velocity of 1.26 rad/s. Each blade is 25.4m long and has a mass of 13,600kg. The height of the tower is 64.6m. If the 3-blade assemble becomes detached and falls to the ground, but continues to rotate, how much kinetic energy does the assemble have when it reaches the ground? [Ans: 32,800,000J]

Answer 1

The rotating unit will have rotational KE of .5Iw². I =2*.333ml² = 13600*25.4² = 8.77 *106 kg-m² thus KE rot = 6.96*10⁶ J. The mass of the unit can be considered as a point 64.6 meters above the surface and that potential will be convert to KE due to the fall. That energy is mgh = 25.9 *10⁶ J. The total is 32.86 *10⁶ J