What Does My Finger Weigh?
On Sun, 4 Sep 2016 16:32:44 -0400, Jeff Wisnia
wrote:
I'm always interested in learning new things to try and spotted this one
in a book of puzzles SWIMBO just gave me. I just had to try it.
Put a paper or Styrofoam cup with water in it on a kitchen or postal
scale and note its weight. Leave it on the scale. (A glass of water
might be too heavy for the scale.)
Now stick a finger or two into the water without touching the side or
bottom of the cup and watch what happens.
The scale reading increases.
Did you expect that? I didn't.
I'm sure any physicists here will explain why.
Jeff
You are exerting a force equal to the bouyancy of your finger on the
cup.
|