Where’s the pressure difference in this trick?
At the opening of the glass. The water inside the glass weighs a pound at best, and, depending on the size of the opening of the glass, the air pressure is exerting 15-30 pounds upward on the bottom of the card. Guess who wins? Tip, when you get good at this experiment, try doing it over a friend’s head!
Materials: a glass, and an index card large enough to completely cover the mouth of the glass.
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I had so much fun with this, but the second time around I got new card stock nd it didn’t work. If you could explain please do. Thank You.
Yes – absolutely try it!
It matters that it’s card stock, right?
Well, I guess I could try it and find out, huh? 🙂 😉