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Why did the duck go up? Any theories? Answered


http://www.youtube.com/watch?v=-x-z3IAD3g8&feature=related

Skip ahead to 4:57. What he refers to as string appears to be an elastic material. He pulls up and it goes up. He pulls down and it goes up. The video is supposed to be about electrostatic toys.

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rickharris
rickharris

10 years ago

Nothing to do with electrostatics. The duck is an example of a differential hoist. The string is wrapped around two differently sized pulleys rather than one continuous string.

Thus when pulled one pulley turns the other hoisting the duck up the second string.

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Vorenus
Vorenus

Answer 10 years ago

I'm vaguely familiar with differential hoists: Differential Pulley

How did they get it to go up either way they pulled? It also went up when they pulled down, as well as up.

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Re-design
Re-design

Answer 10 years ago

Your're right the video is mislabeled. And an excelent explanation of the duck. I couldn't figure it out but understand what's happening.