Question: You have a flywheel with system parameters as shown in Figure 1. Think of the Flywheel as a solid disk with radius R and thickness t, rotating with an angular velocity w. The energy stored in the flywheel U is given as: U = ½ *J* w² Here, J =π/2*p*R*t, is the polar moment of inertia of the disk and p is the density of material of the disk. If the maximum principal stress in a wheel of uniform thickness is given by max = (3+) p R2 w², find an expression for U/m. Using this relation, answer the following: 1) Identify the material index from the relation of U/m. Material: density p. strength a Stress Burst Flywheel shield Figure 1