A ball that bounces on water

Discussion in 'General Science & Technology' started by one_raven, Oct 16, 2008.

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  1. one_raven God is a Chinese Whisper Valued Senior Member

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  3. Steve100 O͓͍̯̬̯̙͈̟̥̳̩͒̆̿ͬ̑̀̓̿͋ͬ ̙̳ͅ ̫̪̳͔O Valued Senior Member

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    Pff, what a con, certain dog balls bounce on water, even small footballs bounce quite well on water.
     
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  5. one_raven God is a Chinese Whisper Valued Senior Member

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    Really?
    I have tried to bounce quite a few different balls on water over the years and it never seems to work.
     
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  7. NGM Registered Member

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    I've watched my Lab jump into the water many times. He must be one type of dog that this isn't true. His balls just follow him into the water.

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  8. one_raven God is a Chinese Whisper Valued Senior Member

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    Maybe they bounce around on the way in.
    Have you ever asked?
     
  9. NGM Registered Member

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    Many times. He's quite a smartass and just refuses to answer me!
     
  10. one_raven God is a Chinese Whisper Valued Senior Member

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    Labs can be like that.
    I had a black lab named Jack.
    Best dog I ever had but stubborn as hell.
     
  11. Steve100 O͓͍̯̬̯̙͈̟̥̳̩͒̆̿ͬ̑̀̓̿͋ͬ ̙̳ͅ ̫̪̳͔O Valued Senior Member

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    Yes. You can probably get most balls to bounce on water if you throw them hard enough.
     
  12. one_raven God is a Chinese Whisper Valued Senior Member

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    It doesn't seem this one needs to be thrown very hard at all.
     
  13. Steve100 O͓͍̯̬̯̙͈̟̥̳̩͒̆̿ͬ̑̀̓̿͋ͬ ̙̳ͅ ̫̪̳͔O Valued Senior Member

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    You don't with a dog ball or a mini football either, they seem to act the same too.

    Stress balls also work very well.
     
  14. one_raven God is a Chinese Whisper Valued Senior Member

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    OK.

    So the science behind it then?
    Why does it work?
    Why do some balls bounce on the surface of water pretty readily, and why do some seem to "stick" to the surface?

    What dynamics are involved?
     
  15. Steve100 O͓͍̯̬̯̙͈̟̥̳̩͒̆̿ͬ̑̀̓̿͋ͬ ̙̳ͅ ̫̪̳͔O Valued Senior Member

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    I'd too like to know.
     
  16. sniffy Banned Banned

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    This thread should be in the physics subforum. Surface tension; force; motion it's all about the physics people.
     
  17. Dr Lou Natic Unnecessary Surgeon Registered Senior Member

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    I think you're wrong steve. You can skim balls on the water, but I really don't think the balls you're talking about would bounce off the water if they were thrown at the angles and speeds these ones are. Watching those videos I'd expect a suction effect to take place and stop the ball dead on a lot of those throws, on others I'd expect a skim but it's bouncing way higher than it should.
     
  18. Syzygys As a mother, I am telling you Valued Senior Member

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    I bet I already posted about this (ball bouncing on water), but I am too lazy to look it up...
     
  19. Steve100 O͓͍̯̬̯̙͈̟̥̳̩͒̆̿ͬ̑̀̓̿͋ͬ ̙̳ͅ ̫̪̳͔O Valued Senior Member

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    I watched the videos, and the balls I have used work just as well.
     
  20. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

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    Looks like the coating has a small coefficient of friction with the water. Remember, all liquids have some non-Newtonian properties (http://www.youtube.com/watch?v=f2XQ97XHjVw you can make it out of corn starch and water). Water has kind of a high surface tension, which is why (for example) belly flops hurt like hell and can knock your breath out of you. So if you throw ANY ball hard enough, it will bounce off of the surface of the water. The coating on THIS ball probably greatly reduces the speed at which you have to throw the ball.

    Of course, this could all be complete bullshit too

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  21. kevinalm Registered Senior Member

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    Reminds me of the pbs series "The Secrets of the Dead" episode about the bouncing dam busting bombs in ww2. I believe the episode was titled "The Dam Busters".
     
  22. draqon Banned Banned

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    maybe the ball has a hadrophobic oil on it or something that increases the surface tension...
     
  23. one_raven God is a Chinese Whisper Valued Senior Member

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    Bouncing Betty, if I recall correctly.
    Maybe Killjoy will see this and confirm.
     
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