Supersonic aircraft
________ required even more drastic changes in airfoil shapes, some losing the roundness formerly associated with a wing and having a double- wedge shape.
Weight
________ is a force that acts opposite to lift.
Lift
________ and thrust are artificially created elements devised to enable an aircraft to fly.
18th century
In the ________ the Swiss mathematician Daniel Bernoulli discovered that, if the velocity of air is increased over a certain point of an airfoil, the pressure of the air is decreased.
thermal techniques
In a sailplane, height attained by mechanical, orographic, or ________ is translated into speed by means of gravity.
jet engine
In a(n) ________, thrust derives from the propulsive force of the rotating blades of a turbine compressing air, which is then expanded by the combustion of introduced fuel and exhausted from the engine.
total lift
Thus, ________ is related to the shape of the airfoil, the angle of attack, and the speed with which the wing passes through the air.
upper surface
Early airfoils typically had little more than a slightly curved ________ and a flat undersurface.
Thrust
________ is obtained by accelerating a mass of ambient air to a velocity greater than the speed of the aircraft; the equal and opposite reaction is for the aircraft to move forward.