



 
Hi Will. Assuming the flywheel is a uniform solid disk, its rotational kinetic energy is ½Iω^{2}, where I is the rotational inertia and ω is the rotational frequency. A solid cylinder has a rotational inertia of ½mr^{2}, so the energy needed to spin it up is ½(½mr^{2})ω^{2} = ¼mr^{2}ω^{2}. This ignores friction or other influences of course. Choose your units appropriately and you should be able to use this formula to calculate your answer, Will. Stephen La Rocque.  


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