gen-define-atmospheric-pressure-and-altitude-and-give-one-short-1427

Define atmospheric pressure and altitude and give one short worked example.

# Definitions **Atmospheric Pressure**: The force per unit area exerted by the weight of air in the atmosphere above a given point. At sea level, standard atmospheric pressure is approximately 101,325 Pa (or 1 atm). **Altitude**: The vertical distance or height of a point above a reference level, typically measured from sea level. --- # Worked Example **Problem**: An airplane is flying at an altitude of 3,000 m. If the atmospheric pressure at sea level is 101,325 Pa, calculate the atmospheric pressure at this altitude. (Use the approximation: pressure decreases by about 12 Pa per meter of altitude gained) **Solution**: Given: - Initial pressure (P₀) = 101,325 Pa - Altitude (h) = 3,000 m - Pressure decrease rate = 12 Pa/m Pressure decrease = 12 Pa/m × 3,000 m = 36,000 Pa Pressure at altitude = P₀ - Pressure decrease Pressure at altitude = 101,325 - 36,000 = **65,325 Pa** (or about 0.64 atm) **Answer**: The atmospheric pressure at 3,000 m altitude is approximately 65,325 Pa.