Mini-Project Air Pressure

Photo Credit: Kevin Chan 5th
Today I help a cup of water upside down while keeping the water in by placing a piece of paper under the opening of the cup. Isn't that great!! Here are the tricks:

• Fill the cup up with water half way.
• Get a thick piece on paper.
• In one quick movement flip the cup to the paper side so that the cup is covered by the paper.
• Then maintain holding the cup upside down with the paper under to keep the air pressure so there will be no leakage.

Science: Atmospheric pressure is the force per unit area exerted against a surface by the weight of air above that surface in the Earth's atmosphere. In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. Low pressure areas have less atmospheric mass above their location, whereas high pressure areas have more atmospheric mass above their location. Similarly, as elevation increases there is less overlying atmospheric mass, so that pressure decreases with increasing elevation.