Aero 1 CH 1 Flashcards
Scalar
Quantity that represents only magnitude. Time, Temp, Volume.
Vector
Quantity that represents magnitude and direction. Displacement, Velocity, Acceleration
Displacement(s)
Distance and direction
Velocity(V)
Speed and direction
Speed
Scalar equal to the magnitude of the velocity vector.
Acceleration(a)
Rate and direction of a boy’s change of velocity.
Force(F)
Push or pull exerted on a body. F=m·a
Mass(m)
Quantity of molecular material that comprises an object
Volume(v)
Amount of space occupied by an object.
Density(ρ)
Mass per unit volume ρ=mass/volume
Weight
Force with which a mass is attracted towards the center of the earth by gravity
Moment(M)
Vector quantity equal to a force(F) times the distance(d) from the point of rotation that is perpendicular to the force.
Work(W)
When a force acts on a body and moves it. W=F·s
Power(P)
Work done per unit of time. P=W/t
Energy
Scalar measure of a body’s capacity to do work. TE=PE+KE
Potential energy(PE)
Ability of a body to do work because of its position or state of being. PE=weight·height=mgh
Kinetic energy(KE)
Ability of a body to do work because of it’s motion. KE=½ mV²
Newton’s first law
Equilibrium
A body in rest tends to remain in 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.
Equilibrium
absence of acceleration either linear or angular.
Equilibrium flight
Sum of all forces and sum of all moments around the center of gravity are equal to zero.
Straight line constant velocity
thrust, drag, lift, and weight acting equally.
Trimmed flight
Sum of all moments around the center of gravity is equal to zero.
Newton’s second law
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 a=Vout-Vin/time
Newton’s third law
Interaction
For every action, there is an equal and opposite reaction.
Atmosphere Composition
78% nitrogen, 21% oxygen, 1% other gasses(argon and carbon dioxide). To be considered uniform mixture of these gasses.
Static pressure (Ps)
The pressure particles of air exert on adjacent bodies.
Ambient static pressure
Equal to the weight of a column of air over a given area.
Air density (ρ)
Total mass of air particles per unit of volume.
Temperature (T)
Measure of the average random kinetic energy of air particles.
Average lapse rate
Rate of temperature change. 2°C (3.57°F) per 1000ft
Isothermal layer
36,000-66,000ft the air remains a constant -56.5°C (-69.7°F)
Humidity
Amount of water vapor in the air. As humidity increases, air density decreases.
Viscosity (μ)
Measure of air’s resistance to flow and shearing. Liquids- as temp increases viscosity decreases
Air-air temp increases viscosity increases
Local speed of sound
Rate at which sound travels through a particular air mass. As temperature increases, the speed of sound increases.
Standard atmosphere
Average zero humidity conditions at middle latitudes.
Static Pressure Pso
- 92 inHg
1013. 25 mbar
Temperature To
59°F
15°C
Average Lapse Rate
3.57°F/1000ft
2°C/1000ft
ρo
.0024 slugs/ft³
1.225g/l
Local speed of sound
- 7 knots
340. 4 m/s
General gas law
P=ρRT
R is a constant for any given gas
Altitude
Geometric height above a given plane reference.
True altitude
Actual height above mean sea level.
Pressure altitude(PA)
Height above the standard datum plane. 29.92 inHg
Density altitude(DA)
The altitude in the standard atmosphere where the air density is equal to local air density. Found by correcting pressure altitude for temperature or humidity deviations from the standard temp.
Aircraft
Any device used or intended to be used for flight in the air.
Airplane
heavier than air fixed wing aircraft that is driven by an engine driven propeller or a gas turbine jet and is supported by the dynamic reaction of airflow over its wings.