2006-06-05 16:15:32 · 14 answers · asked by jlynn 1 in Science & Mathematics ➔ Physics
Things that are orbiting our planet are in a state of constant "free fall". That is why they appear to be weightless. The force of gravity is still very high on the astronaut.
2006-06-05 18:18:25 · answer #1 · answered by avik_d2000 4 · 2⤊ 0⤋
This is awkward because the term "weightless" means different things to different people. A better description is that an astronaut in an orbiting spacecraft is in "free fall". The force of gravity on the astronaut is still very high. For an astronaut on the space station, the gravitational force is only about 6% lower than it is on Earth. However, as the spacecraft, the astronaut, and any loose obects are all falling with the same acceleration, things appear not to fall if released.
Basically, things in an orbiting spacecraft are weightless in the exactly same way as things in a falling elevator. If you consider that to meet your definition of "weightless", then that's what it is.
2006-06-05 23:44:27 · answer #2 · answered by Christopher N 3 · 0⤊ 0⤋
They are weightless in the same sense that you would be weightless if you jumped out of an airplane with a scale and tried to weight yourself on it.
The astronauts in orbit are "weightless" because they are falling towards the Earth, but they never actually get any closer to it because the fact that the Earth is curved and the astronauts are orbiting at many thousand miles per hour, relative to the ground, the ground drops away at the same rate they fall towards it. If the space station or shuttle were to stop orbiting and remain over the same point on Earth, they would indeed fall back to the ground. There IS gravity in space, but the force of gravity from the Earth, or any other celestial body, decreses greatly as you move farther away from it. As a result, the astronauts would not initally fall back to Earth with the constant acceleration of 32 feet per second per second that someone closer to the surface might fall off a building at.
That being said, there are locations in space that may exist for brief moments where the pull on you from say the moon, is equal to the pull on you from the Earth. Here you would truely be weightless.
But you always have mass.
2006-06-06 04:42:52 · answer #3 · answered by minuteblue 6 · 0⤊ 0⤋
NO, since they are still in the earth's gravity well they still have both weight as well as mass.. Technically they are in free fall. They are falling towards the earth, but also have a "forward" velocity so that when they fall enough, they have gone over the curvature of the earth and keep falling around it.
Problem with trying to put them on a scale and weighing them would be that the scale is also falling, so relative to the scale they would have no weight. To experience true weightlessness, they would need to be motionless and be able to be unaffected by the gravity well. But, if the shuttle, or ISS or whatever stopped its forward velocity, it would then start falling straight down and eventually impact.
2006-06-06 02:05:12 · answer #4 · answered by quntmphys238 6 · 0⤊ 0⤋
Well, if you want to be pedantic, you could point out that different parts of his body are at different distances from the centre of the Earth, so there's a very weak tidal force; in other words, if his feet are closer to the Earth than his head, gravity is pulling them slightly more strongly. Quite often the word microgravity is used to indicate that gravity isn't exactly zero in orbit.
2006-06-05 23:22:47 · answer #5 · answered by zee_prime 6 · 0⤊ 0⤋
Umm, I don't think so. Since the sun still has a pull on the astronaut, (and so does the earth, now that I think about it), I know he's still being pulled upon by the sun, and that's called micro gravity, and since gravity gives us weight, maybe he has some kinda micro weight?
2006-06-05 23:20:14 · answer #6 · answered by Mirosan 1 · 0⤊ 0⤋
NO. weight is a force caused by the interaction between gravity and mass. As the astronaut is still being affected by earths gravity he (or she) still has weight)
2006-06-06 08:04:13 · answer #7 · answered by kbr61263 3 · 0⤊ 0⤋
The answer depends upon the definition of weight.
If we take the weight as the force exerted by the body on the earth( it may even on the atmospheic air) then as the spacegraft is not pushing the earth in any way we say it has no weight.
2006-06-06 00:30:09 · answer #8 · answered by Pearlsawme 7 · 0⤊ 0⤋
Gravity is pulling, but the space ship misses the earth, so is in a constant state of free fall, much like a free fall in an airplane.
2006-06-05 23:41:06 · answer #9 · answered by rockEsquirrel 5 · 0⤊ 0⤋
Depends on what you mean by weightless. Yes, the person doesn't feel any external forces. They simply float.
2006-06-05 23:19:08 · answer #10 · answered by something 3 · 0⤊ 0⤋