Physical Science gravity room

Discussion in 'Physical Science' started by yermom, Jan 28, 2005.

  1. yermom

    yermom New Member

    hey. do any of you no about why gravity on earth is stronger than in space? that isnt really my question, and I no the closer the objects, the more pull force there is, but do u no if, and if so, what would be needed to be done to create an environment on earth (like a room) thats weightless like an environment in space? what kind of changes would need to be done and all? besides the elevator trick, any ideas on what has to be done?
     
  2. kiwirobin

    kiwirobin Premium Member

    There is no grafity,
    the earth sucks.

    As far as I'm aware Grafitational force is the attraction between two objects and is relitive to mass.
    Thus there is no grafity in space but objects within space with gravitational attraction.
    If you jump up earths mass attracts your maas towards it. The bigger your mass to attract the faster you fall (terminal velocity).
    It's also what holds electrons in orbit around the nucleas and planets around a sun.
    Do a search on gravity and I'm sure in an hour you'll find loads of corrector info than this.
    As for such a room I suggest you go visit your nearest vertical wind tunnel for some bodyflight.
    IT ROCKS!!!:bounce::bounce::bounce:
     
  3. Young William

    Young William Premium Member

    Zero gravity is not that difficult to attain. NASA.gov provides alot more data than can be fit into this created block.
     
  4. yermom

    yermom New Member

    ok, maybe a new question....

    always found a "weightless room" fascinating. so any of you guys got any ideas on how to make one on earth, or seen any plans for one?:cheers:
     
  5. tablet

    tablet Premium Member

  6. pineappleupsidedown

    pineappleupsidedown Premium Member

    I'm not sure what you mean by "there is no gravity". masses drawing towards each other is basically the defintion of gravity, so to say "there is no gravity, only objects pulling towards each other" doesnt really make sence.

    Objects fall at the same accleration regardless of weight, if you have ever seen the "feather and bowling ball" experiment, what they do is drop those two items inside a vacuum, so there is no air resistance. And they hit the ground at the same time.

    Terminal velocity is when you have so much Frictional Force(air resistance) that you slow down just as much as you are speeding up, so that you no long acclerate, but continue at the same speed.

    A feather has a lot of air resistance, so it reaches terminal velocity much sooner than a bowling ball would, which is why the bowling ball hits the ground before the feather if you droped them both outside of a vacuum.

    I realize you were not sure about the information you were saying, so Im just trying to answer them for you kiwirobin

    ---Pineapple
     
  7. kiwirobin

    kiwirobin Premium Member

    Thanxs for that pineappleupsidedown, I can take all the positive critisism I can get. I doubt everything I know.
    As for the first part that was indeed a joke.
    There is no gravity....the earth SUCKS, get it.
    Oh well.
    But seriously, I am aware of the theory you have just mentioned but I'm pretty sure this is prooved incorrect. I must check this out to be sure but from memory the mass equation figures.
    e.g : if you take a bowling ball,
    and a bowling ball shaped peice of foam of lesser mass,
    and let them go together the mass of the real ball will mean a larger terminal velocity. Even though the surface area to wind resistance is equal for both.
    I'd put my money on it.
    In vacuum this is ofcorse another story because there is no counter attracting mass to be drawn towards.
    In a pure vaccum thus a feather and a 20000000 ton asteroid given the same initial enertia should travel at an equal speed.
    Sounds right to me but again I loved to be proved wrong,:ham:

    I remember also film footage of a similar experiment on the moon (N.Armstrong) with a feather, it indeed hit the ground at the same time as the heavier item (can't remember what).
    Strange result concidering the moon also has a gravitational field, even though much less due to it's lesser mass.
    Maybe a good topic for a seperate thread
    "did man really set foot on the moon?"
    From evidence I have seen I still have my doubts.

    Anyway I'll look into this one further, unfortunatly no time at the moment. Look forward to a solid answer for this one.
    And everyone please be patient with my spelling, it's been awhile that I've used english.
    Hugs to all...
     
  8. kiwirobin

    kiwirobin Premium Member

    Just a final comment --pineapple,
    you said...

    "Objects fall at the same accleration regardless of weight, if you have ever seen the "feather and bowling ball" experiment, what they do is drop those two items inside a vacuum, so there is no air resistance. And they hit the ground at the same time."

    Where is the ground in a vacuum?
    If you let something go in the vacuum of space without excerting any force on it wouldn't it just hang there?
    You can't drop something, you'd have to push it initially groundwards.
    Where's up or down? which direction must it 'fall' to reach the ground?
    Just a thought.
    :puz:
     
  9. kiwirobin

    kiwirobin Premium Member

    Have had a look around and came up with this...

    Each particle of matter attracts every other particle with a force which is directly proportional
    to the product of their masses and inversely proportional to the square of the distance between them.
    The standard formula for gravity is:
    Gravitational force = (G * m1 * m2) / (d2)

    This is what I meant.

    Resistance due to counter forces such as resistance fron atmosphere (friction = heat = slower) has an effect when present.

    To go back to yermom's origional question...
    Weightlessness is more correctly termed microgravity. You are not actually weightless, because the Earth's gravity is holding you and everything in the shuttle in orbit. You are actually in a state of free-fall, much like jumping from an airplane except that you are moving so fast horizontally (5 miles per second or 8 kilometers per second) that, as you fall, you never touch the ground because the Earth curves away from you. It's like this: When you stand on a bathroom scale, it measures your weight because gravity pulls down on you and the scale. Because the scale is resting on the ground, it pushes up on you with an equal force -- this equal force is your weight. However, if you were to jump off a cliff while standing on a bathroom scale, both you and the scale would be pulled down equally by gravity. You would not push on the scale and it would not push back against you. Therefore, your weight would read zero.

    This is basicaly what I tried to explain in the other gravity forum with the carsurfing example.
    To build such a room I believe a method to equally counteract gravitational force on an object is required, like the trains which are lifted of the rails and accelerated by electromagnitism.

    Here are some nice links...
    http://science.howstuffworks.com/
    http://www.curtin.edu.au/curtin/dept/phys-sci/gravity/
     
  10. yermom

    yermom New Member

    yes, this is true. regaurdles of weight thing fall equally, its wind resistance that interferes. so do any of you no how fast something falls (like a bowling ball, basically ANYTHING) just basically, what would be the rate of MPH, or MPS of something falling on a general scale of gravity? and back to the orginal, any of you guys got ideas to make a "weightless" type room?
     
  11. kiwirobin

    kiwirobin Premium Member

    check this link for the formulas
    http://www.grc.nasa.gov/WWW/K-12/airplane/termv.html

    note:The terminal velocity equation tells us that an object with a large cross-sectional area or a high drag coefficient falls slower than an object with a small area or low drag coefficient. A large flat plate falls slower than a small ball with the same weight. If we have two objects with the same area and drag coefficient, like two identically sized spheres, the lighter object falls slower. This seems to contradict the findings of Galileo that all free falling objects fall at the same rate with equal air resistance. But Galileo's principle only applies in a vacuum, where there is NO air resistance and drag is equal to zero.

    which is what I was trying to explain earlier.
    I'll have a think about this room and get back if I have something
     
  12. oddtodd

    oddtodd Premium Member

    You couldn't make a gravity fre room on earth , or anywhere else for that matter . there would always be a gravitational force somewhere that would be pulling on you , and you on it , no matter how slight .

    The shuttle and all the satellites we have are all constaqntly pulled toward the earth . It is the short boosts of foreward momentum that keeps them in orbit and hence a body would be constantly "falling" toward the earth .

    as far as the rate of speed in a vacume(no wind resistance) for a body to fall in earths gravity : The rate is 32 feet per second SQUARED . This simply means that a body falling towards earth starts falling at 32 feet per second , and GAINS speed at 32 feet per second .

    In the first second of fall , a body would have fallen 32 feet , and accelerates an additional 32 feet per second , the math gets exponential as time continues and the resistance of the atmosphere does actually cause a maximum speed threshold to be reached (will look up the value) . without atmosphere to cause friction , we would continually gain speed til we go SPLAT .

    Gravity (in the case of falling towards a planet) has it's force directed at the CENTER of the planet . The surface would stop you quickly , but your momentum is seeking the center point 0f the mass of the object.

    Picture a hole that goes straightr thru the earth that you could jump into , and travel through without hitting anything : You would fall all the way to the other side , but come up a few feet short , and then start falling back down again . Hypothetically , you would fall back and forth losing a few feet each time and end up floating at the center point of the mass.

    Hope that was a bit helpful , need to read up on it a bit myself...
     
  13. kiwirobin

    kiwirobin Premium Member

    Please everyone, try to get Galileo out of your head for this one.
    It doesn't apply.
    Things don't fall at the same speed!
    A human reaches terminal velocity at about 200kph...depending on his WEiGHT. It's mass that counts here.
    I advise you check the link in my last post for clarity.
    oddtodd, wouldn't you burn up when you reached the centre?...lol
     
  14. oddtodd

    oddtodd Premium Member

    Ok , of course things don't fall at the same speed . Things sre attracted by gravity equally is a better way to put it . without an outside influence such as air friction , "things are equally affected by gravity in proporrtion to their size and the distane between them (inverse square law) .

    Let's try to post some links to validate our positions kiwirobin !

    And yes , I would be scorched , but floating at the center of the earth...
     
  15. helenheaven

    helenheaven Premium Member

    okay am trying to school myself up here, this helped!

    There is a legend that says that Galileo once dropped two objects off the Leaning Tower of Pisa to show that the heavier of the two objects dropped faster. If a feather and hammer were the two objects he used then obviously the hammer would hit the ground first. What would happen if this experiment was repeated on the moon? Which of the following would be true;



    The hammer would hit the ground first
    The feather would hit the ground first
    Both would hit the ground at the same time
    None of the above would be true


    On earth there is a thick atmosphere. Therefore there is a large air resistance to a falling object. On the moon, the atmosphere is so thin that it has effective zero air resistance. This is why on the moon the two objects hit the ground at the same time. This experiment was actually carried out by American astronauts on the moon to prove that Galileo was correct in thinking the effect was due to air resistance.

    source: http://www.curtin.edu.au/curtin/dept/phys-sci/gravity/index2.htm
     
  16. kiwirobin

    kiwirobin Premium Member

    If you read carefully oddtodd you will find I have inclueded multiple links in this form.
    The last one with very specific proof to the point I'm trying to make.
    And helenheaven I mentioned the same experiment earlier in this post and also a link to the same source.
    I don't know how I can get this mass concept as I interperate it across any clearer.
    Read my posts again and check out this link...
    Terminal Velocity
    If you still think two objects with differing mass are "attracted by gravity equally" then please get me out of my delusion.
     
  17. kiwirobin

    kiwirobin Premium Member

    This is a direct paste of a site.

    We know that when we add energy to water we produce steam. Steam is molecules of water vibrating at an increased rate. The steam's vibration produces a lower density than water and therefore it floats in water. The more the energy content of a particle the more it "floats" (gravitates) towards othe particles of similar "density". A body is more dense than another when it contains more particles per same unit of volume. More particles means more "space-time bubbles" WARPING the space-time continuum
    http://members.tripod.com/QuantumGravity/

    Got me thinking about diving, we I dive my bouancy is neutralised with the use of weight belts and In essance I am weightless. The water density is so much that without extra weight the air in my lungs makes me rise to the surface. Like steam.
    For such a room we're thinking about the density of the environment must be equal to our own.
    Otherwise we must still look at electro-magnetics or something, I just don't like the idea of being supercooled.
    I'm still not out about the mass thingh but still looking. :help:
     
  18. kiwirobin

    kiwirobin Premium Member

    I think I've found a way to explain my difficulty accepting things equally effected by gravity.

    In a vacuum supposidly a hammer and feather fall at the same rate because of the lack of resistance due to an atmosphere. Even though their mass / weight is different.

    Is it not so that a hammer with mass x also has a gravitational field.
    It falls to the moons surface because the moons gravitational field is larger than it's own.
    But in my thoughts it's also attracting the moon to it at the same time in proportion to it's own mass.
    The feather does this also but to a lesser degree due to it's lesser mass.
    Does that not imply that the feather "falls" slower?

    Someone please straighten me out on this because it's hurtin me head.:bnghd:
     
  19. oddtodd

    oddtodd Premium Member

    I think I figured out what we disagree on : (In a vacume) A bowling ball atracts the earth and vica versa . afeather atracts the earth and vica versa .

    I agree that the feather is less atracted than the bowling ball and there would (or should) be a diference in the rate of fall .

    I think that you would need an immensly dense and huge object compared to it's complete oposite (grain of sand) to notice any appreciatible difference .

    The inverse square law still holds , so gravity is constant in respect to that , it just affects different items seperately .

    Does that make any sense to anyone ? help me get this straight ...\

    edit * I didn't read your last scentence kiwi , LOL ! I almost used the same smilie myself.
     
  20. kiwirobin

    kiwirobin Premium Member

    Yippie, we're both right oddtodd.
    Dang that's satisfying :bouncy:

    So where do we go now for yermom's room?
    Super conducters?...Bbbrrrrrrrr
    Electromagnitism?
    Antigravity?