Why do passengers of high-altitude jet planes feel the sensation of weight while passengers in orbiting spaceships don't?
2006-09-06 16:27:21 · 12 answers · asked by MegN 1 in Science & Mathematics ➔ Physics
DO NOT listen to 99% of the answers you got. They are WRONG!
The gravitational field in a typical orbit around earth is about 9.7 m/s^2. The gravitational field at sea level is 9.8 m/s^2. Being in "space" does not automatically mean that there is no gravity. If you are close enough to earth there is still a very appreciable gravitational field.
THE REASON astronauts float around and don't experience gravity is because they are in orbit. By definition orbit means that they are falling as fast as the earth is passing beneath them. In essence they are constantly falling (which ends up being the exact same thing as no gravity. see the theory of general relativity!).
If you just built a huge elevator (imagine) to the height of the space station, and dropped a wrench from the top, it would fall to the earth. If you stood in this elevator, you would be stuck to the floor just like you are on earth. If you looked out the window from this elevator, you would see objects in orbit whizzing by (the people onboard those objects would be floating around weightless).
Planes operate much closer to earth, and would therefore have to travel much faster to attain orbit. You could work out the speed a plane would have to travel in order to be in orbit. Turns out that this speed is unrealistic for any plane (especially given the drag caused by the atmosphere). However, if you got a plane going that fast (impossible), the people onboard would be weightless.
-Tom
2006-09-06 16:56:43 · answer #1 · answered by tomz17 2 · 1⤊ 0⤋
Orbiting spaceship has the centrifugal force which is equal to gravity force.There is no need to apply any force to keep it in orbit due to very low air friction.It will continue orbiting by inertia for certain period.Astronauts are actually not falling but moving together with spaceship.
The lower the orbit the faster they have to orbit.
If you can make a plane strong enough to wistand air friction heat and powerful enough to obtain very high speed so as centrifugal force equals to gravity then passengers will feel the weightlessness like astronauts.
I guess.
2006-09-07 12:24:47 · answer #2 · answered by dwarf 3 · 0⤊ 0⤋
Even though it is in a high altitude, the plane is still within the gravitational pull of the Earth. Those in space orbiting are not affected (as much). I believe we were taught that it's like a satellite orbiting Earth. It is always in a state of falling towards the ground, but because of the angle it is doing it at, it keeps orbiting the Earth - weightlessly.
2006-09-06 23:34:47 · answer #3 · answered by Rowan E 1 · 0⤊ 1⤋
Becasue passengers in an airplane are still being supported by the airplane. In a sattelite, you're actually falling all of the time, but the forward velocity is enough that you never get to the ground. The ground 'falls away' from under you at exactly the same rate as you fall towards it. That's whu it's called 'free fall'.
But in an airplane that can be simulated by flying a parabolic curve so that the acceleration of gravity is exactly matched by the downwards acceleration of the airplane.
Doug
2006-09-06 23:32:00 · answer #4 · answered by doug_donaghue 7 · 3⤊ 0⤋
It may not seem like it, but airplanes usually only fly around a mile or 2 higher than ground level while spaceships usually orbit at a few hundred miles. Include the factor that gravity-distance relationships are exponential (the affect gravity has on a mass decreases exponentially as distance increases) and you find that the difference of a few hundred miles makes all the difference.
2006-09-06 23:31:30 · answer #5 · answered by cptbirdman 2 · 0⤊ 1⤋
I agree with Tom, except to note that for a circular orbit, velocity is LOWER at lower altitude.
Thus to make geosync orbit requires a much greater expenditure of fuel then putting a payload into a simple low earth orbit does, and most of this is not about height, it is about building tangenital velocity.
Regards, Dan.
2006-09-07 08:52:36 · answer #6 · answered by Dan M 3 · 0⤊ 0⤋
Despite what some of the answers say, there is gravity in space. When in orbit, an object, be it the moon or a satellite, is in continuous free fall. When in free fall, you are weightless. When is a commercial, which fly at around 30,000 ft, or about 5.5 miles, you are not in free fall. You might as well be sitting in your living room as far as gravity goes.
2006-09-06 23:43:34 · answer #7 · answered by wires 7 · 1⤊ 0⤋
Because the spacecraft passengers are going so much faster, and as a result can be in free fall. Aircraft passengers are supported against gravity by the airplane.
2006-09-06 23:30:00 · answer #8 · answered by Anonymous · 1⤊ 1⤋
jet plane is in the earth's gravitational field . While a spaceship is out of it.
2006-09-06 23:35:25 · answer #9 · answered by Dinker 2 · 0⤊ 1⤋
because thers not force of gravity pulling down on them but in high altitude there is gravity
2006-09-06 23:29:38 · answer #10 · answered by lalagag 1 · 0⤊ 1⤋