L3 Flashcards
What is the ideal gas law?
The ideal gas law is
pV=nRT, where:
- p: Pressure
- V: Volume
- n: Amount of substance (moles)
- R: Ideal gas constant
- T: Temperature (in Kelvin)
What is the significance of the ideal gas law in understanding the atmosphere?
The ideal gas law helps describe the behavior of atmospheric gases, relating pressure, volume, and temperature to predict weather and understand atmospheric processes.
What are the key laws combined to derive the ideal gas law?
- Boyle’s Law: p∝1/V (at constant T)
- Charles’ Law: V∝T (at constant p)
- Gay-Lussac’s Law: p∝T (at constant V)
- Avogadro’s Law: V∝n (at constant T and p)
What is the hydrostatic equation?
The hydrostatic equation relates the change in atmospheric pressure with altitude:
dp/dz = - pg
- dp = pressure change
- dz = altitude change
- p = air density
g = gravitational acceleration
What is the blackbody radiation law?
Blackbody radiation describes how objects emit energy based on temperature. Stefan-Boltzmann’s law is:
F=ϵσT 4
where:
- F = energy emitted
- ϵ = Emissivity (how well an object emits radiation)
- σ = Stefan-Boltzmann constant (5.67 x 10^-8 Wm ^-2 K ^-4)
- T = temperature in kelvin
What is Stefan-Boltzmann’s law?
Total energy emitted by a blackbody is proportional to the fourth power of its temperature:
I=σT ^4
What is Wien’s law?
Wien’s law relates the temperature of a blackbody to the wavelength of its maximum intensity
λ max = 2897/T
where λ max is the peak wavelength (in micrometers) and T is temp in Kelvin
What is Kirchhoff’s law of radiation?
Absorptivity equals emissivity for an object in thermal equilibrium
What is latent heat?
Latent heat is the energy required for a substance to change its phase (e.g., solid to liquid) without changing its temperature.
How is the first law of thermodynamics expressed for an ideal gas?
dU = dQ + dW
where:
- dU = change in internal energy
- dQ = heat added to the system
- dW = Work done on/by the system
for adiabatic processes (dQ = 0):
dU = dW
What is the mixing ratio in atmospheric science?
The mixing ratio is the mass of a chosen gas compared to the mass of dry air.
What are the laws of motion?
- A body remains at rest or in uniform motion unless acted upon by an external force.
- F = ma : Acceleration is proportional to the force and inversely proportional to mass.
- For every action, there is an equal and opposite reaction.
What are the laws of thermodynamics?
- Zeroth Law: If A is in thermal equilibrium with C, and B is in equilibrium with C, then A and B are in thermal equilibrium.
- First Law: Energy cannot be created or destroyed, only transformed
- Second Law: Entropy of an isolated system cannot decrease.
- Third Law: As T -> 0, entropy approaches a minimum value.
What is the specific heat capacity?
The amount of heat required to raise the temperature of 1 kg of a substance by 1 K.
How is the ideal gas law modified for mixtures of gases?
p=∑p i
Each gas in a mixture obeys the ideal gas law individually, and the total pressure is the sum of partial pressures (𝑝𝑖)
