A Future Use of Space Stations May Be to Provide

A future use of space stations may be to provide hospitals for severely burned persons. It is very painful for a badly burned person on Earth to lie in bed. In a space station, the effect of gravity can
Be reduced or even eliminated. How long should each rotation take for a doughnut-shaped
Hospital of 200-m radius so that persons on the outer perimeter would experience 1/10 the normal
Gravity of Earth?

A) 91 min
B) 1.5 min
C) 0.011 min
D) 8.7 min
E) 4.6 min