Hey Ray: Water magic
PITTSBURGH (KDKA) — We have shown you several experiments dealing with air pressure, and we want to show you how to perform an air pressure experiment that looks like magic.
Our atmosphere is always pushing on us in all directions. Containers that seem empty are filled with air. Even when you turn that container upside down, it is full of air. Even when a container is full of something else, like water, air is still pushing on it.
Also, this could get messy, so make sure you are doing this experiment in a place that is OK to get wet.
Physics creates magic when we put our experiment together. For this, we need a playing card and a small glass of water with an opening smaller than the playing card.
Set the playing card on top of the glass.
While holding the playing card onto the glass of water, quickly flip it upside down.
Now let go of the card!
So, how does that card stay put, and why isn't the water spilling out?
That is the magic, or the physics. Since the tiny bit of air in the container is quickly pushed out of the container by the water, there is no air in it.
Air is trying to fill that empty space created when the glass was turned upside down, and that air pushes the playing card against the glass, holding the card in place and keeping the water from spilling.
Now, what happens when you slide the card away?
Exactly what you think: It will allow air to move in, and the water to spill out.
So, there is a little science disguised as magic.
