EASA Principles of Flight Practice Test

Dynamic pressure is the pressure associated with the motion of air relative to the aircraft. It is defined by q = 0.5 * rho * V^2, where rho is air density and V is true airspeed. This quantity represents the kinetic energy per unit volume of the moving air and is the part of the pressure that acts on surfaces to produce lift. Because it depends on the square of speed, dynamic pressure increases rapidly as speed rises; and because it depends linearly on density, it increases with denser air. So, for the same speed, higher density gives higher dynamic pressure, and for the same density, increasing speed raises dynamic pressure with the squared relationship. The stated formula and the note that it increases with airspeed and air density capture the correct relationship. The other formulations miss the 0.5 factor, use the wrong dependence on velocity, or imply an inverse relationship, which doesn't match how dynamic pressure behaves.