An astronaut is training for deployment to the international space station. They must undergo g force testing by sitting in a special machine that rotates to simulate the force of gravity. In order to pass their test, they must stay conscious and alert under a force of at least 7.6 g's (7.6 times the gravitational acceleration). If the radius of the machine is 9.4 m, what is the speed of rotation (in m/s) needed to simulate the g force requirement?