What effect does an increase in altitude have on air pressure?

• A. Pressure increases due to less air
• B. Pressure increases due to more air
• C. Pressure decreases due to less air
• D. Pressure remains constant regardless of altitude

Answer: (C)

An increase in altitude leads to a decrease in air pressure primarily because the density of air diminishes as one moves higher in the atmosphere. At lower altitudes, the atmosphere is compressed by the weight of the air above it, resulting in higher pressure. As altitude increases, the amount of air above decreases, which reduces the overall weight pressing down from above. Consequently, there are fewer air molecules and less air mass, leading to lower air pressure at higher elevations. This relationship is important in various fields, including meteorology, aviation, and environmental science, as it affects weather patterns, flying conditions, and human physiology.