Wednesday, March 17, 2010

Swimming coin

Experiment from Ania&Andriej

To our experiment we need a bowl of water and a coin. We want to show you that mettalic coin can hang on the water surface. We put the coin onto the water.
Why it doesn't sink like majority of mettalic things?
It doesn't sink, because cohesion force is big enough to keep the coin on the water surface.


  1. A very interesting experiment

    I try with coins of different sizes

  2. I have some problems with this experiment.
    I tried the experiment with very small coins. But the coin does not float
    How do you leave the coin in the water? I suppose you left the coin in the water on a piece of paper.

  3. You can do it with your fingers. Just don´t touch the water surface!

  4. The coin I tested at home is 50 heller and 10 halerzy (czech equivalent eurocent).
    Other suitable coins are 1 or 2 russian ruble and ukrainian copeck.

    I will record laying a coin onto water surface with fingers.

  5. you have to take a lightweight coin for example german 1 pfening