Winds
What is wind? It is air moving from one place to another! Wind is very important to pilots. A windy day can be both good and bad: A breeze can push you along to your destination, or make it very difficult to land at your airport. Yet it is a factor we have no control over.
Close to the ground wind speed is much less than at higher altitudes. This is because the surface of the ground creates friction with the air. This has an effect up to about 3000 feet. Higher than this, the winds follow a set of "rules".
Imagine that you have a bottle of pop.
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