General #2 Flashcards
Define Pi
A constant that expresses the relationship between the circumference of a circle and it’s diameter
=3.1416
Define matter
Any substance that occupies space and has mass
Matter may exist in what three states?
Solid
Liquid
Gas
Define kinetic energy
Energy in motion
Work is the product of what two factors?
Force and the distance moved
W = F x D
What is British Thermal Unit
Heat energy required to change the temperature of 1 pound of water 1 degree Fahrenheit
Three methods of heat transfer
Conduction
Convection
Radiation
What term defines the temperature at which all molecular motion ceases?
Absolute zero
Units to express hydraulic or pneumatic pressure in the United States
PSI, (Pounds per square inch)
Describe how pressure is transmitted when a force is applied to a confined liquid
Pressure is transmitted equally in all directions
Approximate speed of sound at sea level on a standard day?
661 knots or 340 meters per second
Atmospheric pressure at sea level on a standard day?
29.92 inches of mercury
Temperature on a standard day
59 degrees in Fahrenheit
15 degrees in Celsius
Relative humidity
The ratio between the amount of moisture present in the atmosphere as compared to the amount the air could hold if it were completely saturated
Four principle forces acting on an airplane in flight
Drag
Lift
Thrust
Gravity
Angle of attack
The angle between the relative wind and the chord line of an airfoil
What are the factors that cause an airplane wing to stall?
When the angle of attack exceeds a critical value and the airflow separates from the upper surface and becomes turbulent
Principle effects that result from lowering the flaps while in flight
Lift increases, drag increases, and stall speed decreases
What is the function of a wing mounted vortex generator?
Delay or keep the airflow from separating from the upper surface of a wing during high speed flight
Enhance aerodynamic performance by manipulating airflow patterns
How does blade-flapping help to compensate for dissymmetry of lift in helicopter main rotor systems?
Flapping increases the angle of attack and lift on the retreating blade and decreases the angle of attack and lift on the advancing blade
How does the airflow through the main rotor of a helicopter change during the transition from normal flight to autorotation?
During normal flight the air moves downward and during autorotation the air moves upward
What elements are required to form an electrical circuit?
- A source of electrical energy
- A load or resistance to use the electricity
- Wires or conductors to connect the source to the load
DC circuits can take one of three forms or types. What are they?
- Series
- Parallel
- Complex (series-parallel)
Absolute humidity
The ratio of the amount of water vapor in a mixture of air and water
Dewpoint
Temperature to which the air must be cooled to become saturated
Purpose of wing dihedral
Increase lateral stability
