Question

A 4.20 m diameter merry-go-round is rotating freely with angular speed of 0.800 rad/s. Its total moment of inertia is 1260 kg m squared. How much work will bring the merry-go-round to rest?

Answer 1

Let's evaluate the rotational kinetic energy (RKE) possessed by the system. \[RKE = {1 \over 2} I \omega^2\]Now, from the Work-Energy Theorem, \[W = \Delta E = \Delta RKE\]