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Astronauts and objects inside an orbiting spacecraft appear weightless mainly because:
AThe value of g is exactly zero at that height
BThere is no air to support their weight
CThey are all in a state of free fall together
DThe spacecraft moves faster than escape velocity
Answer & Solution
Correct answer: C. They are all in a state of free fall together
1. At the height of a space station, $g$ is only about 11% less than its surface value, not zero.
2. So height is not the reason for weightlessness.
3. The only force on the orbiting craft is gravity, so the craft, the travellers and the objects are all in free fall.
4. Since free-fall velocity is independent of an object's properties, a released object stays put relative to the astronaut and seems weightless.
5. Absence of air and zero $g$ are misconceptions, so those options are wrong.
_Source: Balbharati (Maharashtra Board) Class 10 Science & Technology, Ch 1 "Gravitation", p.23_
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