Concept #1: Intro to Rotational Kinetic Energy
Practice: A flywheel is a rotating disc used to store energy. What is the maximum energy you can store on a flywheel built as a solid disc with mass 8 x 104 kg and diameter 5.0 m, if it can spin at a max of 120 RPM?
Example #1: Mass of re-designed flywheel
Practice: When solid sphere 4 m in diameter spins around its central axis at 120 RPM, it has 10,000 J in kinetic energy. Calculate the sphere’s mass.