Define dynamic pressure.

• A. ambient pressure
• B. static pressure
• C. additional pressure caused by air in motion
• D. total pressure

Answer: (C)

Dynamic pressure is the pressure generated by the motion of air relative to the aircraft. It’s the extra pressure above the surrounding static (ambient) pressure that results from the aircraft’s airspeed. In a Pitot-static system, total pressure equals static pressure plus dynamic pressure, and the difference between total and static pressures gives the dynamic pressure, q = 1/2 ρ V^2. This is the part of pressure that relates directly to how fast the air is moving past the aircraft and is what we use to compute indicated airspeed. Ambient pressure is just the surrounding atmospheric pressure, static pressure is the pressure at a point in the airflow without regard to motion, and total pressure is the sum of static and dynamic pressures. Dynamic pressure matches the description of the option: the additional pressure caused by air in motion.