The figure below shows a picture of American astronaut Clay Anderson experiencing weightlessness onboard the International Space Station.
(a) Most people have the misconception that a person in a spacecraft is weightless because he or she is no longer affected by gravity. Show that this premise cannot be true by computing the gravitational field of the Earth at an altitude of 200 km, the typical altitude of a spacecraft in orbit. Compare this result with the gravitational field on the surface of the Earth.
(b) Why would astronauts in orbit experience weightlessness even if they are experiencing a gravitational field (and therefore a gravitational force)?
