Air Pressure
Air is composed of molecules. Air is matter. It has mass and takes up space. Air is composed of different gases such as nitrogen, oxygen, carbon dioxide, water vapor, and other gases. Air molecules are in constant motion. As they move, they come in contact with surfaces. Air molecules push and press on the surfaces they contact. The amount of force per unit area that air molecules exert on a surface is called air pressure. (What is Air Pressure 6) Air pressure is caused by all of the air molecules in the Earth's atmosphere pressing down on the Earth's surfaces. We can measure air pressure to help us predict weather conditions around the world. Temperature also affects air pressure because air contracts when it cools and expands when it is heated. So if air above a region of Earth cools, it does not extend to as high an altitude as the surrounding air. In this case, its pressure at higher temperature is lower than in the surroundings even when the pressure at the......
Join Now or Login to view the rest of this paper.
Approximate Word Count: 450
Approximate Pages: 2 (260 words per double-spaced page) |