What Happens When You Drop a Slinky
High speed cameras finally put the myth to rest.
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27
7. orion commented 12 years ago
Like #1 and #2 said, this is a misleading and childish explanation.
While the spring above the bottom is stretched, it is properly "hanging" on the higher parts of the slinky, its environment is exactly the same as before the top is released. The same holds if there is a tennis ball there. At the moment of release, the forces are unbalanced only for the topmost part. The disturbance then propagates downwards like waves.
If you observe the center of mass, it falls just like any other object. Only the shape of the object changes in a way that some parts remain stationary for a while. Kinda like a falling cat, only the cat's motion is much more complicated.
While the spring above the bottom is stretched, it is properly "hanging" on the higher parts of the slinky, its environment is exactly the same as before the top is released. The same holds if there is a tennis ball there. At the moment of release, the forces are unbalanced only for the topmost part. The disturbance then propagates downwards like waves.
If you observe the center of mass, it falls just like any other object. Only the shape of the object changes in a way that some parts remain stationary for a while. Kinda like a falling cat, only the cat's motion is much more complicated.
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9. loadrunner commented 12 years ago
What walks down stairs, alone or in pairs
and makes a slinkity sound?
A spring, a spring, a marvelous thing!
Everyone knows it's Slinky...
and makes a slinkity sound?
A spring, a spring, a marvelous thing!
Everyone knows it's Slinky...
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13. detonatordan commented 12 years ago
What a large amount of mis-wording, Hey I was once rewarded a pardon from a judge for a cop mis-wording my charges by saying I knowingly did a misdeed!The bottom of the slinky knows nothing! It knows absolutely nothing! Idiocy in human communication! It just doesn't reacts to the force of gravity that's pulling the top half down until it reaches it! And no one could prove what I knowingly or not knowingly did by automatically saying that I knowingly did it, because, as the judge said: "No one knows what I know"!ingly am doing or not!' Anyways this video is stupid!
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14. gouranga4ever commented 12 years ago
The Australian version of physics..
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15. MurderVictim commented 12 years ago
Two confused idiots attempting to confuse even more people.
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25. LaoMa commented 12 years ago
#7 kind of said this already, but to hopefully make it clear for everyone, here goes:
Both ends have a tension caused force vector towards the center point of the coil equal to the gravitational force. We can know this because the lower part is stationary and the Slinky is symmetrical. When the top is released the bottom still has the same forces in effect as it had before. The top however now lacks one force - the hand - and thus starts moving. Because the coil is so soft, the new downward force vector doesn't transfer to the bottom until they pretty much collide.
A more rigid coil would most likely start moving at the bottom too, as the kinetic energy of the falling top would partially transfer to the bottom part. A completely rigid object would (obviously) have both its ends moving instantly.
Basic kinetics in action.
Both ends have a tension caused force vector towards the center point of the coil equal to the gravitational force. We can know this because the lower part is stationary and the Slinky is symmetrical. When the top is released the bottom still has the same forces in effect as it had before. The top however now lacks one force - the hand - and thus starts moving. Because the coil is so soft, the new downward force vector doesn't transfer to the bottom until they pretty much collide.
A more rigid coil would most likely start moving at the bottom too, as the kinetic energy of the falling top would partially transfer to the bottom part. A completely rigid object would (obviously) have both its ends moving instantly.
Basic kinetics in action.
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26. roady commented 12 years ago
What is this "downward force vector doesn't transfer " rubbish? You are as bad as the guy in the clip. The slinky is in free fall. Because the stretching force on it before it started was gravity, when it was released the ends accelerated towards the middle at roughly the acceleration of gravity (it is a spring, storing force exactly is what we use them for). The top is accelerating down at G + G, the bottom is doing G - G until the spring is used up. And G - G = 0 so no relative motion.
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27. Steelhunky commented 12 years ago
Kind of like what Wall Street has done to us!
+29 1. Limberg commented 12 years ago