OMEGA }^{2}}r=m\{g+4{{\PI }^{2}}{{n}^{2}}r\}\] \[=m\LEFT\{ g+\left( 4{{\pi }^{2}}{{\left( \FRAC{n}{60} \RIGHT)}^{2}}r \right) \right\}=m\left\{ g+\left( \frac{{{\pi }^{2}}{{n}^{2}}r}{900} \right) \right\}\]