The preliminary design for a "small" space station to orbit the earth in a circular path consists of a ring (torus) with a circular cross section as shown. The living space within the torus is shown in section $A,$ where the "ground level" is $20 \mathrm{ft}$ from the center of the section. Calculate the angular speed $N$ in revolutions per minute required to simulate standard gravity at the surface of the earth $\left(32.17 \mathrm{ft} / \mathrm{sec}^{2}\right) .$ Recall that you would be unaware of a gravitational field if you were in a nonrotating spacecraft in a circular orbit around the earth.