Weighing Astronauts. This procedure actually has been used to "weigh" astronauts in space. A 42.5kg chair is attached to a spring and allowed to oscillate. When it is empty, the chair takes 1.30 s to make on complete vibration. But with an astronaut sitting in it, with her feet off the floor, the chair takes 2.54 s for one cycle. What is the mass of the astronaut?