An astronaut whose weight on the Earth is 600 N experiences weightless- ness on International Space Station orbiting around the Earth. It means that

Correct option is B

The Correct answer is (b) normal reaction of the space-station floor on the astronaut is zero. When an astronaut experiences weightlessness in the International Space Station (ISS), it means that both the astronaut and the space station are in free fall towards the Earth, moving at the same velocity. As a result, there is no normal force acting between the astronaut and the floor of the space station, creating the sensation of weightlessness. This condition is known as microgravity. Explanation: The astronaut still experiences Earth's gravitational pull, which keeps the space station and the astronaut in orbit, but because both are falling towards Earth together, no contact force (normal force) is felt between the astronaut and the surface of the station. The feeling of weight is a result of the normal force from a surface pushing against a body (e.g., the ground pushing up against you on Earth). Since this force is absent in the ISS, the astronaut feels weightless. Information Booster: Weightlessness in space is not due to the absence of gravity but due to the free-fall motion of the space station and everything inside it. The ISS orbits the Earth in a state of continuous free fall, which is why objects inside appear to float. The astronaut’s weight, which is the gravitational force acting on them, still exists, but the absence of a normal reaction force leads to the sensation of weightlessness.