Embed Size (px)
Citation preview
WHAT GOVERNS THE WAY THAT GASES, IN OUR ATMOSPHERE, BEHAVE?
CHARLES’ LAW
Molecules of gas at a fixed pressure andtemperature, vibrate sufficiently to
occupy a fixed volume
Warm
CHARLES’ LAW
Warm
Increased molecularvibration, spacing
increases
CHARLES’ LAW
Warm
Volume Increases
Increased molecularvibration, spacing
increases
CHARLES’ LAW
Cool Warm
Volume Increases
Increased molecularvibration, spacing
increases
CHARLES’ LAW
Cool Warm
Volume Increases
Increased molecularvibration, spacing
increases
Decreased molecularvibration, spacing
decreases
CHARLES’ LAW
Cool Warm
Volume IncreasesVolume Decreases
Increased molecularvibration, spacing
increases
Decreased molecularvibration, spacing
decreases
CHARLES’ LAW
Cool Warm
Volume IncreasesVolume Decreases
Increased molecularvibration, spacing
increases
Decreased molecularvibration, spacing
decreases
CHARLES’ LAW“If the atmospheric pressure is held constant, hot gases expand to occupy
a bigger volume and cold gases contract to occupy a smaller volume.”
Cool Warm
Volume IncreasesVolume Decreases
Increased molecularvibration, spacing
increases
Decreased molecularvibration, spacing
decreases
V=k2.TAt constant Pressure
CHARLES’ LAW
Cool Warm
Volume IncreasesVolume Decreases
Increased molecularvibration, spacing
increases
Decreased molecularvibration, spacing
decreases
V↓=k2.T↓ V↑=k2.T↑
CHARLES’ LAWV=k2.T
At constant Pressure
M =1.0
BOYLE’S LAWMolecules of gas at a fixed pressure and
temperature, vibrate sufficiently tooccupy a fixed volume
M =1.0
BOYLE’S LAW
Atmospheric Pressure
Vibrating molecules of gas
M =1.0M = 0.5
M = 1.0
BOYLE’S LAWCompress,squeeze, add“weight”
M = 0.5
M =1.0M = 0.5
M = 1.0
BOYLE’S LAWCompress,squeeze, add“weight”
Decompress,relax, reduce“weight”
Increased PressureVolume contracts
Decreased PressureVolume expands
M = 0.5
M =1.0M = 0.5
M = 1.0
“At constant temperature, the pressure exerted on a gas is inversely related to the volume the gas occupies – gases are compressible.”
BOYLE’S LAW
M = 0.5
M =1.0M = 0.5
M = 1.0
P↑ ….. V↓P↓…. V↑
BOYLE’S LAWP = k1/V
At constant Temperature
HOW ARE THESE LAWS GOING TO HELP TO MOVE MASS AND ENERGY IN THE ATMOSPERIC SYSTEM?
Air Filled Balloon
EQUAL PRESSURE (ATMOSPHERIC)
Brick
HigherPressure
LowerPressure
Air Flow
Differences in pressures causemotion of the air
Air temperature ≈ Sensible heat fluxfrom insolation= f(latitude,season)
V=k2.TAt constant Pressure
Air temperature ≈Sensible heat fluxfrom insolation= ∫ (latitude,season)
Changes in temperaturecause changes in volume
occupied by air.
V=k2.TAt constant Pressure
P = k1/VAt constant Temperature
Air temperature ≈Sensible heat fluxfrom insolation= ∫ (latitude,season)
Changes in temperaturecause changes in volume
occupied by air.
Changes in volume occupiedcause changes in pressure on
air
V=k2.TAt constant Pressure
P = k1/VAt constant Temperature
Air temperature ≈Sensible heat fluxfrom insolation= ∫ (latitude,season)
Changes in temperaturecause changes in volume
occupied by air.
Changes in volume occupiedcause changes in pressure on
air
Differences in pressure causemovements within the
atmosphere
V=k2.TAt constant Pressure
P = k1/VAt constant Temperature
Air temperature ≈Sensible heat fluxfrom insolation= ∫ (latitude,season)
Changes in temperaturecause changes in volume
occupied by air.
Changes in volume occupiedcause changes in pressure on
air
Temporal and spatialdifferences in insolationrelated to pressure that
moves atmosphere
Differences in pressure causemovements within the
atmosphere
THE EQUATION OF STATE FOR AN IDEAL GAS.
PUTTING IT ALL TOGETHER!
P = R. ρ. T
P = Pressure on a gasR = Gas Constantρ = Density of gasT = Temperature of gas
P = R. ρ. T
P = Pressure on a gasR = Gas Constantρ = Density of gasT = Temperature of gas
?
P = R. ρ. T
P = Pressure on a gasR = Gas Constantρ = Density of gas: ρ = Mass/VolumeT = Temperature of gas
P = R. M/V. T
P = Pressure on a gasR = Gas Constantρ = Density of gas: ρ = Mass/VolumeT = Temperature of gas
P = R. M. T V
Charles’ Law: Fixed P, T and V directly related
9 = 1. 1 . 2.25 0.25
9 = 1. 1 . 3.0 0.33
If T rises to 3.0, thenV must rise to 0.33 toKeep P constant at 9!
P = R. M. T V
Boyle’s Law: Fixed T, P and V inversely related
3. 3 = 1. 1. 9 4. 2.25 = 1. 1. 9
V . P = R. M. T
Multiply bothsides by V
Pressure declinesso volume occupiedincreases to keep T constant
P = R. ρ. T
PRACTICAL APPLICATION
We know that Atmospheric Pressure declines with altitude, so what can weexpect to happen to Temperatures and the Density of the air as you climb a mountain or go up in an airplane?
P = R. ρ. T
PRACTICAL APPLICATION
We know that Atmospheric Pressure declines with altitude, so what can weexpect to happen to Temperatures and the Density of the air as you climb a mountain or go up in an airplane?
Should become colder and the atmosphere “thinner”!
P = R. ρ. T
PRACTICAL APPLICATION
We know that Atmospheric Pressure declines with altitude, so what can weexpect to happen to Temperatures and the Density of the air as you climb a mountain or go up in an airplane?
Normal Lapse Rate: Rate at which temperatures decline (increase) with increase (decrease) in altitude
P = R. ρ. T
PRACTICAL APPLICATION
We know that Atmospheric Pressure declines with altitude, so what can weexpect to happen to Temperatures and the Density of the air as you climb a mountain or go up in an airplane?
Normal Lapse Rate: Rate at which temperatures decline (increase) with increase (decrease) in altitude
6.5°C per Kilometer3.6°F per 1000 ft.
