Chapter 4, Principles of Flight Flashcards
Our atmosphere (air) is composed of 78 percent ____________, 21 percent ____________, and 1 percent other gasses.
Nitrogen & Oxygen
How does a gas, such as air, act when placed in a container?
It conforms to the shape and takes the entire volume of the new container
What is the property of a fluid that causes it to resist flowing?
Viscosity
What is the resistance that one surface or object encounters when moving over another?
Friction
Name the layer of molecules that adhere to a surface when a fluid passes along that surface.
Boundary layer
What is the resistance to airflow called?
Drag
What is the force applied in a perpendicular direction to the surface of an object often measured in pounds of force exerted per square inch of an object (PSI)?
Pressure
How will an object completely immersed in a fluid will feel pressure?
Around the entire surface
What direction will an object move if the pressure on one surface of the object becomes less than the pressure exerted on the other surfaces?
Toward the lower pressure
What is the average pressure, in pounds per square inch (psi), exerted by the weight of the atmosphere under standard conditions at sea level?
14.70
What happens to the pressure exerted by the atmosphere on an object as the object increases altitude?
Pressure decreases with altitude
What happens to the pressure of a fluid moving along a surface as its relative velocity increases?
Pressure decreases with velocity
Which part of a wing moving through the air has the least amount of pressure?
The top
