Moment of Inertia and Rotational Kinetic Energy (Problem 60)

An aircraft is coming in for a landing at 300 meters height when the propeller falls off. When it comes off, the propeller has a rotation rate of 20 rev/s, a moment of inertia of $70.0{\text{kg-m}}^2$, and a mass of 200 kg. If air resistance is present and reduces the propeller’s rotational kinetic energy at impact by 30%, what is the propeller’s rotation rate at impact?