An airplane propeller is 2.14m in length (from tip to tip) with mass 107kg and is rotating at 2900rpm (rev/min) about an axis through its center. You can model the propeller as a slender rod. What is the kinetic rotational energy ? Suppose that, due to weight constraints, you had to reduce the propeller's mass to 75.0% of its original mass, but you still needed to keep the same size and kinetic energy. What would its angular speed have to be, in rpm?