Many times I have found myself watching a baseball game and wondering, "Why does the ball curve?" I have also questioned why airplanes can fly; now I know. An eighteenth century scientist, named Daniel Bernoulli, devised Bernoulli's Principle. He discovered that as the speed of a fluid increases, the pressure decreases. A fluid can be either a liquid or a gas, such as air. This is why airplane wings are designed flat on the bottom, and curved across the top. The air going over the top of the wing must move much faster to keep up with the air beneath the wing. Thus, the pressure above the wing is lower, so the airplane takes flight. This is how airplanes are able to fly. .
I have observed that when driving, semi-trucks seem to pull my car towards them. This is due to Bernoulli's Principle. The air trapped between our vehicles is moving so fast, that it decreases the pressure enough to attract my car to the semi. I have learned that riding behind a semi is a way to save gas. I can put my car in neutral and allow the semi's air pressure power my motion. Once again I can thank Bernoulli for his observation and studies. .
The pitcher verifies the runner at first, winds up, and sends the ball right down the center of the plate. Then at the last second, the ball takes a violent curve out past the bat, STRIKE. The ball curves because of the spin the pitcher puts on it as he releases the ball. The ball keeps turning on itself until the pressure on the left is so diminished, that the ball takes a turn into the decreased pressure. The curve ball has been used to win baseball games from as long as anyone can remember to today. .
Bernoulli's Principle can easily be seen through a venturi Tube. A venturi tube is used in the carburetors of many engines. A venturi tube is only a normal tube, that has a center which is narrower that both ends. When the air pushes through the center, the air must speed up, thus the pressure should be less than at either end.
