An astronaut whose weight on the Earth is 600 N experiences weightlessness on International Space Station orbiting around the Earth. It means that
acceleration of the astronaut is zero
normal reaction of the space station floor on the astronaut is zero
gravitational pull of earth on the astronaut is zero
space station applies a centrifugal force on the astronaut
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC NDA-2 – 2024
– The ISS and everything in it, including the astronaut, are constantly in freefall around the Earth. They are orbiting because they have a high tangential velocity while simultaneously accelerating towards the Earth due to gravity.
– In freefall, there is no supporting surface providing a normal reaction force to counteract gravity. The feeling of weight comes from this reaction force. Since this support force is absent, the astronaut feels weightless.
– The gravitational pull of Earth on the astronaut is not zero in orbit; it is still significant (around 90% of Earth’s surface gravity at ISS altitude) and is what keeps the ISS in orbit.
– The astronaut is accelerating towards the Earth (centripetal acceleration required for circular motion), so their acceleration is not zero.
– Centrifugal force is a fictitious force experienced in a rotating frame of reference; it’s not a real force causing weightlessness.