Aero Basic Theory 2-1 Flashcards
Define Scalar
A quantity that represents only magnitude
Speed, Mass, Density, Volume, Power, Energy, Work, time, temperature
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Define Vector
A quantity that represents Magnitude and Direction.
Velocity, Force, Moment, Weight, Displacement, Acceleration,
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Define Mass
The Quantity of Molecular material that comprises and object.
Define Volume
The amount of space occupied by an object.
Define Density
Mass per unit volume.
Define Force
Mass X Acceleration.
Define Weight
The Force with which a mass is attracted toward the center of the earth by gravity.
Define Moment
Is created when a force is applied at some distance from an axis or fulcrum, and tends to produce rotation about that point.
Define Work
Is done when a force acts on a body and moves it.
Define Power
The rate of doing work or work done per unit of time.
Define Energy
Measure of a body’s capacity to do work.
Define Potential Energy
The ability of a body to do work because of its position or state of being.
Define Kinetic Energy
The ability of a body to do work because of its motion.
Explain, Newtons First Law.
Law of Equilibrium,
“A body at rest tends to remain at rest and a body in motion tends to remain in motion in a straight line at a constant velocity unless acted upon by some unbalanced force.”
Explain Equilibrium Flight.
Exist when the sum of all forces AND the sum of all moments around the center of gravity are equal to zero.
(A/C in straight and level flight at a constant velocity.)
(When these forces exactly cancel each other out.)
L+W=0 T+D=0
Explain Trimmed Flight.
Exist when the sum of all moments around the center of gravity is equal to zero.
(Sum of forces not equal zero)
(A/C @constant rate & constant angle of bank is Trimmed)
A/C in Equilibrium flight is in Trimmed Flight.
Explain Newtons Second Law.
Law of Acceleration.
“An unbalanced force(F) acting on a body produces an acceleration(a) in the direction of the force that is directly proportional to the force and inversely proportional to the mass(m) of the body.”
a = F/m
Explain Newtons Third Law.
Law of interaction.
“For every action, there is an equal and opposite reaction;
the forces of 2 bodies on each other are always equal and directed in opposite directions.”
Define Static Pressure.
(Ps)
The pressure particles of air exert on adjacent bodies,
Ambient Ps is equal o the weight of a column of air over a given area.
**force of Ps ALWAYS act perpendicular to any surface that the air particles collide with.
Define Air Density.
(p)
Total mass of air particles per unit of volume.
*Distance between individual air particles increase with altitude resulting in fewer particles per nit volume.
**air density decreases with an increase in Altitude.
Define Temperature.
(T)
Measure of the average random kinetic energy of air particles.
Decrease 2 C(3.57 F) per 1000ft until 36000ft.
Define Lapse Rate.
Rate of Temperature change.
2 C(3.57 F) per 1000ft until 36000ft 36000ft to 60000ft (T) remains constant -56.5 C(-69.7 F) —Isothermal Layer.
Define Humidity.
Amount of water vapor in the air.
**humidity increases, air density decreases.
Define Viscosity.
A measure of the air’s resistance to flow and shearing.
- *Air - Temp. Increases, Air Viscosity increases.
- *liquid- Temp. Increases, Viscosity decreases.
Define Local Speed of Sound.
The rate at which sound waves travel through a particular air mass.
- *SOS in air, is dependent only on Temperature of the air.
- **Temperature increases, SOS Increases.
Define Standard Atmosphere.
Engineering Baseline.
Static Pressure - 29.92 in.Hg & 1013.25 mbar
Temperature - 59 F & 15 C
Describe General Gas Law
Static Pressure, Air Density, Temperature, Altitude
P = pRT (P-pressure, p-density, T-temperature)
***increase in temperature,decrease in density and vice versa
Explain Bernoulli’s Equation
The sum of Static Pressure(ps) and Dynamic Pressure(q)
ps- pressure particles of air exert on adjacent bodies, wt of column of air over a given area.
q-=1/2pV^2, measure of impact pressure of air moving together.
H = ps + 1/2pv^2 or H = ps + q
Define Steady Airflow.
Exist at every point in the airflow Static Pressure, Density(p), Temp, Velocity remain constant over time. Velocity of every particle that passes ANY Given Point is always the same.
*Air particles follows the same path as the preceding particle.
Define Streamline.
The path that air particles follow in a STEADY Airflow.
**In steady airflow, particles do not cross streamlines.