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.
(W1BSV + Brass Rat '57 EE)
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