Density, Pressure & Temperature Flashcards
Which gas law is defined below?
At a constant temperature, the volume of a gas is inversely proportional to its pressure
Boyles Law (PV = K1)
P = pressure (Pa)
V = Volume (m^3)
K1 = Constant (Joules)
If a contained with fixed amount of molecules inside is reduced in volume, more molecules hit the sides, causing greater pressure
Which gas law is defined below?
The volume of gas at a constant pressure is directly propotional to its absolute temperature
Charles Law (V = K2T)
T = Absolute temperature (Kelvin)
K2 = Constant produced
Which gas law is defined below?
The pressure of an atmosphere is simply the sum of pressures of the individual gases within the atmosphere
Daltons Law (Ptotal = P1 + P2 + P3 + Pn)
Ptotal = sum of all pressures
Pn = Individual pressure
Which gas law is defined below?
The amount of gas dissolved in a liquid is proportional to the gas pressure outside of the liquid.
If the pressure of a liquid is reduced, then the amount of gas dissolved in the liquid will reduce
Henerys Law (P = Kh C)
P = partial pressure
C = concentration of the solute
Kh = Constant with dimensions of pressure divided by concentration
What is Boyles Law
At a constant temperature, the volume of a gas is inversely proportional to its pressure
Pressure increases, volume decreases
What is Charles Law
At a constant pressure, the volume of gas is directly proportional to its absolute temperature.
If temperature increases, volume increases
What is Henrys Law
The amount of gas dissolved in a liquid is proportional to the gas pressure outside of the liquid.
If the pressure of a liquid is reduced, then the amount of gas dissolved in the liquid will reduce
Think about the squeezed bottle and water. Release the bottle cap, the water turns into cloud
What is Daltons Law
The pressure of an atmosphere is simply the sum of pressures of the individual gases within the atmosphere
Ptotal = P1 + P2 + P3
As pressure decreases, what happesn to density
DECREASES
As temperature decreases, what happens to density
INCREASES
The ____ in density due to ____ in altitude has ____ effect than the ____ in density due to ____ reduction
INCREASE // MORE // TEMPERATURE // INCREASE // DECREASE
- DECREASE in density
- INCREASE in altitude
- MORE effect
- INCREASE in density
- TEMPERATURE reduction
Aircraft performance is better in MORE or LESS dense air
MORE
What is the most important criteria impacting aircraft performance
AIR DENSITY
What does an altimeter measure
PRESSURE
When flying from low pressure to high pressure, what will the altimeter read
UNDER READ
Higher than you think you are
When flying high pressure to low pressure, what will the altimeter read
OVER READ
Lower than you think you are
What is an ASR
ALTIMETER SETTING REGION
The pressure setting within an ASR is known as what
REGIONAL PRESSURE SETTING
(RPS)
The RPS pressure setting given to pilots is what
what are the 2 criteria
- LOWEST forecast
- NEXT 2 hours
What are the 3 levels your altimeter can be set to
In reference to datum, not the subscale i.e. QNH
- ALTITUDE
- HEIGHT
- FLIGHT LEVEL
What is QNH and what is it referenced to
- Measure of ALTITUDE
- Reference MEAN SEA LEVEL
What is QFE and what is it referenced to
- Measure of HEIGHT
- Reference AIRFIELD ELEVATION
What is Standard Pressure Setting (SPS) and what is it referenced to
- FLIGHT LEVEL
- 1013 hPa
At what point is it known as when the altimeter of a climbing aircraft is changed from QNH to Flight Level
TRANSITION ALTITUDE
At what point is it known as when the altimter of an aircraft descending is changed from Flight Level to QNH
TRANSITION LEVEL
Where can a pilot obtain the Transition Altitutude
Published in the UK AIP
Where can a pilot obtain the Transition Level
Notified by ATC
What is the space between the transition level and transition altitude known as
TRANSITION LAYER
The transition level is ABOVE or BELOW the transition altitude
ABOVE
Points of equal temperature are known as what
ISOTHERMS
What are altimeters calibrated against
International Standard Atmosphere (ISA)
+15℃
1.225 kg/㎥
-2℃ per 1000 ft
Deviation from ISA will result in altimeter error i.e. when its coler or warmer outside than ISA
Why is a column of warm air taller than a column of cold air
LESS DENSE
Warm air expands, molecules further apart
Pressure levels in warm air are more widely spaced
When temperature increases with altitude, this is known as what
TEMPERATURE INVERSION
Visibility beneath the inversion layer is GOOD or POOR
POOR
Dust and smoke particles get trapped at the inversion layer
What is an air mass descending called
SUBSIDENCE
Subsidences in are are associated with which pressure systems
HIGH PRESSURE
(Anti Cyclone)
What are 3 causes of inversion
- SUBSIDENCE
- FRONTAL
- RADIATION
