Other Materials (In Addition to Those Given in Table 18 $18.3$

Other materials (in addition to those given in Table 18.3) have properties that are compatible with the construction of flywheels with high energy storage capabilities. (Although these materials may not always be convenient in other respects for the construction of a flywheel). Calculate the maximum energy storage capabilities for a 1 kg disk-shaped flywheel made of the following materials, and compare these results with those for the materials in Table $18.3$ .
$\begin{array}{lll}\hline \text { material } & \begin{array}{l}\text { density } \\\left(10^{3} \mathrm{~kg} / \mathrm{m}^{3}\right)\end{array} & \begin{array}{l}\text { tensile strength } \\\left(10^{9} \mathrm{~N} / \mathrm{m}^{2}\right)\end{array} \\\hline \text { bamboo } & 0.4 & 0.5 \\\text { graphene } & 1.0 & 130.0 \\\text { kevlar } & 1.44 & 3.76 \\\text { zylon } & 5.8 & 1.56 \\\text { boron } & 2.46 & 3.1 \\\hline\end{array}$