This video demonstrates that the force resulting from air pressure acts upwards too.
Here is what you need:, large plastic bowl, glass, water, sheet of paper, 1. Place the glass into the plastic bowl., 2. Fill the glass to the rim with water., 3. Cover the mouth of the water-filled glass with the sheet of paper., 4. Turn the glass upside down, while pressing the paper to the mouth of the glass., What do you think?, Why does the water not spill out?, Explanation:, The force resulting from air pressure acts upwards upon the sheet of paper., This force is greater than the weight of the water inside the glass and therefore it does not let the sheet of paper fall down, keeping the water in the glass., 5. A few minutes later: