Physics · Gravitation · NEET
No. At the height of a low satellite (about 400 km) g is still around 8.7 m/s2, close to the surface value 9.8 m/s2. Gravity is very much present. The astronaut feels weightless only because there is no support force pushing back on them, not because gravity vanished.
Weight that you 'feel' is really the normal force from the floor pushing up on you. In orbit, both the astronaut and the satellite are accelerating downward at the same rate g (they are in free fall). So the floor does not press on the astronaut and the astronaut does not press on the floor. Normal force N = 0, so apparent weight = 0. The astronaut floats.
Two different reasons. In a satellite, g is NOT zero but both bodies fall together so apparent weight is zero. In deep free space far from Earth, Sun and all stars, the actual gravitational field g is nearly zero, so real weight (mg) is itself zero. Same feeling of floating, but one is 'free fall with real gravity' and the other is 'no gravity'.
Yes, for a short time. In a freely falling lift (if the cable breaks), or at the top of a jump, or in a diving free fall, you and the surroundings fall with the same g, so N = 0 and you feel weightless. This is exactly the same free-fall mechanism as in a satellite.
No. Mass is the amount of matter and stays the same everywhere. Only the apparent WEIGHT (the support force you feel) becomes zero. Mass never becomes zero in a satellite or in free space.
Two astronauts are floating in gravitational free space after losing contact with their spaceship. The two will:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Weightlessness is the state where the apparent weight (the support or normal force you feel) is zero. It happens when a body is in free fall, so nothing pushes back against it, even though real gravity may still be acting.
Yes. A satellite is continuously falling towards Earth, but its large sideways (tangential) speed makes it keep missing the Earth and curve around it. This continuous free fall is exactly why everything inside feels weightless.
If the satellite fires its engines or rotates to create artificial gravity, there is an extra force and the astronaut is no longer in pure free fall, so they feel weight again. In steady orbit with engines off, they are weightless.
Gravity provides exactly the centripetal force needed to keep the satellite in its circular path. It is all 'used up' bending the path, leaving no force to press the astronaut against the floor, so apparent weight is zero while gravity is fully present.
Yes. Free-fall acceleration g is the same for all masses at that location, so the astronaut, the satellite and a floating pen all accelerate together at the same g. That is why they stay floating relative to each other.
