## anonymous 4 years ago In order to simulate weightlessness for astronauts in training, they are flown in a vertical circle. If the passengers are to experience weightlessness, how fast should an airplane be moving at the top of a vertical circle with a radius of 1770 m?

You want the centripetal force F_c to be exactly equal to the gravitational force. Now $F_c = m \frac{v^2}{r}$ Set that equal to the gravitational force and solve for $$v$$.