Solve the all parts of given question in detail:
Question: An airplane propeller is 2.00m in length (from tip to tip) with mass 130kg and is rotating at 3000rpm (rev/min) about an axis through its center. You can model the propeller as a slender rod.
Question I: what is its rotational kinetic energy in J?
Question II: 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?
I need expert help to solve the above question.