How does atmospheric pressure change with altitude?

• A. It remains constant as altitude increases
• B. It decreases as altitude increases
• C. It increases as altitude increases
• D. It fluctuates randomly

Answer: (B)

Atmospheric pressure decreases with altitude due to the reduction in the weight of the air above as one ascends. The atmosphere is composed of layers of gases held by gravity, and as you move higher, there is less air above you, resulting in lower pressure. This phenomenon can be attributed to the fact that air density also decreases with altitude; there are fewer air molecules in a given volume as you ascend, leading to lower pressure.

Understanding this concept is crucial for pilots and meteorologists because significant variations in atmospheric pressure are involved in weather patterns and flight operations. For instance, the pressure changes can influence weather systems, altitude adjustments in aircraft operation, and the performance of altimeters.