Physics ch 10 homework 13f

Question

An energy storage system based on a flywheel (a rotating disk) can store a maximum of 3.3 MJ when the flywheel is rotating at 1.9×104 revolutions per minute.

What is the moment of inertia of the flywheel?

Answer 1

The kinetic enrgy i s

Ke  =0.5 I w^2

I= 2 Ke/(w^2)

I= 2 x 3.3 x 10^6/( 2 x pi 1.9×10^4 /60)^2

I= 1.67 kg m^2