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02-02-2007, 09:34 PM
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#31
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Join Date: Feb 2004
Location: Oakland, CA
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Originally Posted by graywolf624
Your arguements aren't all that clear guys. You aren't clearly denoting the objects acceleration.
In absolute terms:
F= mass x acceleration. The force of gravity is directly related to the mass of the object (duh). Your simultaneously changing both the F orce of gravity and the mass on the other side in the same proportion. Thus the masses cancel out leaving acceleration to be unaffected by the individual masses. It is a simple algebra problem. The two items will accelerate and travel at the same speed no matter what the mass. F=G(Mem1/r^2)=m1*a m1 cancels out to G(ME/r^2)=a Where Mass of the earth (Me) Mass of the object m1. r= distance from earth. a= acceleration of object. G= gravitational constant
Thus the rate of acceleration of the object dropped only depends on the distance from the earth!
But... And I say but..
If you take the same objects acceleration relative to the earth you have to account for the movement of the earth itself due to the object.
The earth is accelerating towards the item that is dropped. And the bigger the object the greater the force on the earth.
Again the equation is F=G(Mem1/r^2)= Me*a.... This time Me cancels
Giving you G(m1/r^2)=a on the earth.... Meaning the acceleration of the earth is proportional to the weight of the object.
Thus the answer becomes, what frame of reference are you watching the object from. If you are watching from earth there would be an acceleration difference. If you are watching from a frame of reference from somewhere off planet the objects will accelerate with the same rate.
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^ Thank you for clearing that up.
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02-02-2007, 11:53 PM
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#32
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Join Date: Nov 2004
Location: Sydney, Australia
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Not taking into account drag, I would have thought, like Graywolf, that acceleration would be the same, thus the two items would fall at the same rate.
However, in the real world, there is drag, and items will obviously fall at different speeds, and the more aerodynamically efficient ones will fall quicker. Still, weight will not be relevant. Right?
I really should stick to history and philosophy. This science stuff is too complicated.
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02-03-2007, 12:43 AM
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#33
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Join Date: Oct 2003
Location: Hellaware USA
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However, in the real world, there is drag, and items will obviously fall at different speeds, and the more aerodynamically efficient ones will fall quicker. Still, weight will not be relevant. Right?
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Let me say first that I have very little background in fluids. In terms of modeling it with physics, your starting to get over my head when you get into drag.
That being said I am sure the mass of the object falling is important, but other aspects are as well. With aerodynamic drag there are so many factors you probably could not get the same result with 2 runs of the same object. Some of these include the surface area of the object, shape of the object, and speed of the object.
Then you have density of the air, temperature of the air, pressure, direction of air flow, etc (which are all interrelated.)
The air provides a force to the object pushing up.. the object pushes down on the air. Remember from the equations above the force of the falling object is f=m1a where a is a constant 9.8 m/s^s.
So now we pick a heavier m1. The force of the heavier object falling is now higher since we just showed its non earth relative acceleration is constant. This means if it hits the air and encounters the same friction force (aka all else equal), the net force pushing downwards afterwards will be higher then that of a lighter object. A great F with the same mass means a greater acceleration. Thus a heavier object all else being equal will have a higher resistance (momentum) to the slowing effect of the airodynamic drag.
Info on calculated drag and the like.
http://hypertextbook.com/physics/matter/drag/
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Common Sense- so rare it's a super power.
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02-03-2007, 01:06 AM
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#34
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Join Date: Dec 2003
Location: Atlanta
Posts: 2,610
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On a side note, ae86_16v have you seen the film of the astronauts on the Moon dropping the feather and the hammer to prove Galileo’s theory on gravity correct? Its very cool to see what happens without air resistance.
Ahh, and of course its on youtube:
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1992 Toyota Celica GT 5spd, intake.
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02-03-2007, 01:22 AM
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#35
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Join Date: Feb 2004
Location: Oakland, CA
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Originally Posted by sentra_dude
On a side note, ae86_16v have you seen the film of the astronauts on the Moon dropping the feather and the hammer to prove Galileo’s theory on gravity correct? Its very cool to see what happens without air resistance.
Ahh, and of course its on youtube:
http://www.youtube.com/watch?v=WOvwwO-l4ps&eurl= |
Yeah definitely  . I also saw the one in a vacuum tube too, that was cool.
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02-03-2007, 02:55 AM
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#36
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Join Date: Feb 2004
Location: Sacramento, CA
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When I take a shit, the bigger poop causes a larger splash onto my buttocks, but I think that doesn't have to do with the speed at which it fell into the toilet so much as the mass of my poop, and the water it displaced. So, I don't think this example is very helpful. Sorry. 
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Still Reposting, Still Pimping
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02-03-2007, 02:58 AM
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#37
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Regular User
Join Date: Feb 2004
Posts: 305
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You guys are debating newtonian physics. It is nothing but a generalization. Gravity doesn't even exist.
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02-03-2007, 03:09 AM
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#38
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Join Date: Jan 2004
Location: north-south of nowhere
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^^ how do your balls hand downwards then ...
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02-03-2007, 03:54 AM
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#39
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Join Date: Sep 2003
Location: Ann Arbor, Michigan, USA/ Bloomington, IN, USA
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Originally Posted by graywolf624
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However, in the real world, there is drag, and items will obviously fall at different speeds, and the more aerodynamically efficient ones will fall quicker. Still, weight will not be relevant. Right?
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Let me say first that I have very little background in fluids. In terms of modeling it with physics, your starting to get over my head when you get into drag.
That being said I am sure the mass of the object falling is important, but other aspects are as well. With aerodynamic drag there are so many factors you probably could not get the same result with 2 runs of the same object. Some of these include the surface area of the object, shape of the object, and speed of the object.
Then you have density of the air, temperature of the air, pressure, direction of air flow, etc (which are all interrelated.)
The air provides a force to the object pushing up.. the object pushes down on the air. Remember from the equations above the force of the falling object is f=m1a where a is a constant 9.8 m/s^s.
So now we pick a heavier m1. The force of the heavier object falling is now higher since we just showed its non earth relative acceleration is constant. This means if it hits the air and encounters the same friction force (aka all else equal), the net force pushing downwards afterwards will be higher then that of a lighter object. A great F with the same mass means a greater acceleration. Thus a heavier object all else being equal will have a higher resistance (momentum) to the slowing effect of the airodynamic drag.
Info on calculated drag and the like.
http://hypertextbook.com/physics/matter/drag/ |
... Sounds about right to me (says the physicist).
As far as Schroedinger's cat is concerned...
The infamous Schroedinger's cat problem is a thought experiment that has applications to quantum mechanics and various other high-level strains of physics.
Basically it is this:
We place a living cat into a steel chamber, along with a device containing a vial of hydrocyanic acid. There is, in the chamber, a very small amount of a radioactive substance. If even a single atom of the substance decays during the test period, a relay mechanism will trip a hammer, which will, in turn, break the vial and kill the cat. The observer cannot know whether or not an atom of the substance has decayed, and consequently, cannot know whether the vial has been broken, the hydrocyanic acid released, and the cat killed. Since we cannot know, the cat is both dead and alive according to quantum law, in a superposition of states. It is only when we break open the box and learn the condition of the cat that the superposition is lost, and the cat becomes one or the other (dead or alive). This situation is sometimes called quantum indeterminacy or the observer's paradox: the observation or measurement itself affects an outcome, so that it can never be known what the outcome would have been if it were not observed.
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me-- "Sometimes you feel like a nut, sometimes you don't. Sometimes I feel like the moon is made of cheese"
my Hindibonics-speaking Indian roommate--"Dawgs, do you have any idea how much bacteria that would take?"
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02-03-2007, 08:26 AM
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#40
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Join Date: Jan 2007
Location: Basel, CH
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oh and btw the person who first finds gravity waves or the medium that the gravitational force is transportet in, wil lget the Nobel prize of physics.
that's what my physics professor said yesterday
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02-03-2007, 08:31 AM
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#41
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Join Date: Nov 2006
Location: United Provinces of the Kingdom of Great Netherlands
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Results 1 - 10 of about 1.480.000 for gravity waves (0,10 seconds)
*sigh* Have you ever tried Google?
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02-03-2007, 12:36 PM
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#42
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Join Date: Jan 2007
Location: Basel, CH
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Although gravitational radiation has not yet been directly detected, it has been indirectly shown to exist.
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please do some research before you try owning somebody :roll:
here's the full article on it: http://en.wikipedia.org/wiki/Gravitational_wave
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"Some say that the outline of his left nipple is exactly the same shape as the Nürburgring, and that if you give him a really important job to do, he'll skive off and play croquet... all we know is, he's called the Stig."
The Top Gear Wikiquote
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02-04-2007, 12:20 AM
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#43
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Join Date: Mar 2005
Location: Campos, Brazil
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They fall the same speed.
Want to make a test? Just get a book and a sheet of paper, make the book bigger in area than the paper. Then just put the paper on top of the book (on the cover) and let it loose. They will fall together, same speed, same time.
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02-04-2007, 12:42 AM
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#44
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Join Date: Sep 2003
Location: Ann Arbor, Michigan, USA/ Bloomington, IN, USA
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Originally Posted by Z3uS
They fall the same speed.
Want to make a test? Just get a book and a sheet of paper, make the book bigger in area than the paper. Then just put the paper on top of the book (on the cover) and let it loose. They will fall together, same speed, same time.
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That has more to do with the aerodynamic properties of the book and the fact that the turbulence that forms on top of the book would force the paper to lie flat against the surface of the book.
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me-- "Sometimes you feel like a nut, sometimes you don't. Sometimes I feel like the moon is made of cheese"
my Hindibonics-speaking Indian roommate--"Dawgs, do you have any idea how much bacteria that would take?"
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02-04-2007, 01:27 AM
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#45
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Regular User
Join Date: Jan 2004
Location: north-south of nowhere
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Do heavier objects "fall" faster?
well ... as i see it .. not being a dork and all ...
heavier objects acclerate to terminal velocity faster then lighter objects ....
that is if you take out wind speed drag coefficients and shit .... like you read in the science books back in school " In Perfect Condition " ..
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