# Calculating the kinetic energy of a flywheel

Question asked by David Nolan on Dec 14, 2020
Latest reply on Dec 15, 2020 by David Nolan

I'm trying to calculate the kinetic energy of a flywheel that I created inside of solidworks, When I calculate it the result is way off. I think it's because the moment of inertia is too low. So the value its giving me is 0.00009054 kg * metres squared for a 70mm diameter brass disk that is 10mm thick with some holes cut in it. It weighs 0.29 kilograms and it rotates at 20 radians a second. When I put those figures into the formula Ef = 1/2 I ω^2... It's meant to give me the energy value in joules and it does, only the value is less then one joule which is sounds way too low. Anyone know where I'm going wrong?

Can Solidworks even calculate this kind of thing accurately. I'm not sure and I know you could do the math manually for such a simple shape but I want to know how to do it inside of solidworks in case I need to calculate more advanced flywheels.