In Order to Simulate Weightlessness for Astronauts in Training,they Are

Multiple Choice

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 2.5 km?

A) 79 m/s
B) 310 m/s
C) 260 m/s
D) 160 m/s
E) 510 m/s