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ESS 102
N/A
59
Aerospace Engineering
Undergraduate 1
01/31/2011

Additional Aerospace Engineering Flashcards

 


 

Cards

Term
What is the approximate black body temperature of the sun?
Definition
6,000K
Term
In which part of the electromagnetic spectrum does the sun emit the most power?
Definition
Visible
Term
How does this part of the spectrum (visible) interact with the Earth's atmosphere and surface?
Definition
It passes through the earth's atmosphere and is absorbed by Earth's surface
Term
What is the approximate black body temperature of earth?
Definition
300K
Term
In which part of the electromagnetic spectrum does the sun emit the most power?
Definition
IR
Term
How does this part of the spectrum (IR) interact with with the Earth's atmosphere and surface?
Definition
It is reflected between the surface and the atmosphere and is absorbed by H2O and CO2
Term
What is different about the atmosphere of Venus compared to Earth that makes it so much hotter?
Definition
Venus has significantly more CO2 than earth, so the greenhouse effect is intensified.
Term
Write down the 3 steps in the proton proton chain. Include the approximate time each step takes.
Definition
Step 1: p+p --> D+e^+Ve
sub: e(+)+e(-) --> 2 gamma (10^10 years)
step 2: D+p --> 3He + gamma (.5 seconds)
step 3: 3He + 3He --> 4He + 2p (10^6 years)
Term
Why does the first step take so long to occur?
Definition
The two proteins repel eachother
Term
What conditions in the core allow this first step to occur? What additional piece of physics is needed to understand how two protons can fuse together?
Definition
It must be very hot and very dense. Quantum tunnelling is needed to understand.
Term
Explain why this process gives off energy (proton proton) Think einstein.
Definition
E=MC2. This process gives off energy because 4He has more mass than 4 protons
Term
Who was the famous space tourist mentioned in lecture/what did he do?
Definition
He built the first commercial aircraft.
Term
How many ergs/second (old units) are there in one watt (modern unit)?
Definition
10^7
Term
How many gigawatt power stations would it take to equal the energy output of the Sun?
Definition
4 x 10^17
Term
Question Group 2: A home has a power bill given in kilowatt-hours (kWh), which is the number of hours over which you used one kW of power. Suppose you were billed for 180 kW hours last month.
How many ergs of energy did you consume?
Definition
6.5 x 10^15
Term
Suppose the energy you used was divided into 60 W light bulbs (0.06 kW). How many bulbs would need to be on continuously in your house to account for your bill if a month is exactly 31 days?
Definition
4
Term
What is the ratio (Esun/Eusa) of the total energy output of the Sun in one second (Esun) to the amount of energy used by the entire United States in a year (Eusa)?
Definition
2x10^8
Term
Question Group 3: The distance between the Earth and the Sun is known as an astronomical unit (AU) and is equivalent to 1.5 ×108 km. Use this information to answer the questions below.

How fast is the Earth moving around Sun in km/s?
Definition
30 km/s
Term
Question Group 3: The distance between the Earth and the Sun is known as an astronomical unit (AU) and is equivalent to 1.5 ×108 km. Use this information to answer the questions below.

The solar constant for the Earth is approximately 1300 W/m2. The planet Neptune is 30 AU from the Sun. What is the solar constant at Neptune?
Definition
1.4 Watt/m^2
Term
If the density of iron is 7.87 g/cm^3, what is the density in kg/m^3?
Definition
7870 kg/m^3
Term
What is a helium atom (4He) composed of (neutral not ionized)?
Definition
2 protons, 2 neutrons, 2 electrons
Term
Which of the following statements are TRUE concerning the Bohr Model?
a. Energy states are continuous
b. Energy states are quantized or discrete
c. The energy state closest to the nucleus has the largest energy.
d. Most of the atom is empty space other than a dense negatively charged nucleus.
e. Most of the atom is empty space other than a dense positively charged nucleus.
Definition
B and E
Term
What happens when an atom absorbs a photon of light that has energy greater than its atomic binding energy?
a. Neutron becomes unbound from the atom
b. Electron falls to a lower energy level
c. Proton becomes unbound from the atom
d. Proton falls to a lower energy level
e. Electron becomes unbound from the atom
Definition
E
Term
A plasma consists of ____.
. neutral atoms
b. neutral molecules
c. Free (unbound) electrons
d. Atomic ions
e. Molecular ions
Definition
C, D, E
Term
Which of the following occur when an electron falls to a lower energy level?
a. Atom emits a proton with an energy exactly equal to the electron's change in energy.
b. Atom absorbs a photon with an energy exactly equal to the electron's change in energy.
c. Atom emits a neutrino with an energy exactly equal to the electron's change in energy.
d. Atom emits a photon with an energy exactly equal to the electron's change in energy.
Definition
D
Term
In the stratosphere, the temperature _______.

a. decreases with altitude due to photochemistry
b. decreases with altitude due to spontaneous emission
c. increases with altitude due to photochemistry
d. increases with altitude due to scattering
e. increases with altitude due to ionization
Definition
C
Term
Which radiative transfer process correctly describes how greenhouse heating of our atmosphere works. (Hint: The 2 primary greenhouses gases are CO2 and H2O).

a. Discrete Molecular energy level transitions let visible sunlight in, but are stimulated by the Earth's outgoing infrared blackbody radiation.
b. Atomic and Molecular Electronic energy states scatter much of the incoming solar radiation, which heats the atmosphere.
c. Discrete Atomic energy level transitions let visible sunlight in, but are stimulated by the Earth's outgoing infrared blackbody radiation.
d. Discrete Molecular energy level transitions are stimulated by solar ultraviolet radiation to heat the atmosphere.
Definition
A
Term
Hydrogen and oxygen react to form water and release 487 kJ of energy. Use E=mc2 to determine the mass difference between the hydrogen + oxygen compared to the water.

a. The water has the same mass as the hydrogen and oxygen.
b. The water is about 5 x 10^(-12) kg less than the hydrogen and oxygen.
c. The water is about 2x 10^(-3) kg more than the hydrogen and oxygen.
d. The water is about 2x 10^(-3) kg less than the hydrogen
e. The water is about 5 x 10^(-12) kg more than the hydrogen and oxygen.
Definition
B
Term
Why are molecular spectra more complex than atomic spectra?

a. There are many more molecules than atoms.
b. Atoms are less massive than molecules so their energy differences are smaller.
c. Molecules have more electrons, which means more transitions are possible.
d. Rotational and vibrational modes add extra energy levels between which transitions can occur.
Definition
D
Term
They are large subatomic fragments consisting of 2 protons and 2 neutrons.

a. Alpha Correct.
b. Gamma
c. Beta
Definition
A
Term
They are high-energy electrons ejected from the nucleus of an atom when a neutron becomes a proton.
Choose one answer.
a. Beta
b. Gamma
c. Alpha
Definition
A
Term
They are packets of energy (photons) released from the nucleus of unstable atoms.
Choose one answer.
a. Alpha
b. Gamma
c. Beta
Definition
B
Term
They are composed entirely of energy (zero mass) and travel at the speed of light.
Choose one answer.
a. Gamma
b. Alpha
c. Beta
Definition
A
Term
They are negatively charged.
Choose one answer.
a. Gamma
b. Alpha
c. Beta
Definition
C
Term
What is the first step of the proton chain?
Choose one answer.
a. e+ + D + neutrino -> p + p
b. D + p ->3He + gamma ray
c. p + p -> e+ + D + neutrino , e+ + e- -> gamma ray
d. 3He + p ->4He
e. 3He + 3He ->4He + 2p
Definition
C
Term
What is the second step of the proton chain?
Choose one answer.
a. e+ + D + neutrino-> p + p
b. p + p -> e+ + D + neutrino , e+ + e- -> gamma ray
c. 3He + 3He ->4He + 2p
d. 3He + p ->4He
e. D + p ->3He + gamma ray
Definition
E
Term
What is the third step of the proton chain?
Choose one answer.
a. D + p ->4He + neutrino
b. p + p -> e+ + D + neutrino + e- -> gamma ray
c. 3He + p ->4He
d. D + p ->3He + gamma ray
e. 3He + 3He ->4He + 2p
Definition
E
Term
Which are of the following are true regarding the theory that the Sun's power is generated by its own collapse?
Choose at least one answer.
a. This process could power the sun for 22 million years
b. This process could power the sun for 4.5 billion years
c. This theory holds today
d. This theory is outdated and no longer accepted
e. This process requires the Sun's radius to shrink by 50 m per year
Definition
A, D, E
Term
Why is the surface of Venus so hot compared to all the other planets? (check all that apply)
Choose at least one answer.
a. Current volcanic activity
b. Solar radiation is trapped by N2 in the atmosphere (the greenhouse effect)
c. High winds
d. Solar radiation is trapped by CO2 in the atmosphere (the greenhouse effect)
e. It is the closeest to the Sun
Definition
D
Term
What happens when an atom absorbs a photon of light that has energy greater than its atomic binding energy?
Choose one answer.
a. Electron falls to a lower energy level
b. Electron becomes unbound from the atom
c. Proton becomes unbound from the atom
d. Proton falls to a lower energy level
e. Neutron becomes unbound from the atom
Definition
B
Term
Which of the following statements are TRUE concerning the Bohr model of the atom?
Choose at least one answer.
a. Most of the atom is empty space other than a dense positively charged nucleus.
b. Most of the atom is empty space other than a dense negatively charged nucleus.
c. Energy states are quantized or discrete
d. The energy state closest to the nucleus has the largest energy.
e. Energy states are continuous
Definition
A, C
Term
What is scientific notation?
Definition
A shorthand way of writing and multiplying large (and small) numbers
Term
How does the size of the sun compare to the size of the earth?
Definition
approximately 10,000 km larger
Term
Ratio of sun's math to earth's mass?
Definition
3.3 x 10^5
Term
Basic composition of earth (land and air) and sun
Definition
Sun: Hydrogen, helium, carbon, iron
Earth air: nitrogen, oxygen, water, argon, co2, methane
Earth (full): iron, oxygen, silicone, magnesium,
Term
Sun vs. Earth temperature
Definition
Sun:
surface: 6000K
atmosphere: 2 million K
core: 15 million K

Earth
surface: 300K
atmosphere: 200-1000K
interior: 3000-5000K
Term
Density Earth v. Sun
Definition
about 4 g cm earth is denser
Term
Energy produced by the sun?
Definition
Sun outputs 4x10^26 watts. Sun dominates energy and light production at all frequencies
Term
What is light?
Definition
visible portion of electromagnetic spectrum
Term
Speed of light?
Definition
3.0 x 10^8 m/s
Term
What are photons?
Definition
Small bundles of energy (light)
Term
How do photons move?
Definition
A photons energy is proportional to frequency. A photons frequency is proportional to wavelength.
Term
What is the electromagnetic spectrum?
Definition
Speed? how much distance wave moves
Frequency? number of peaks that pass a location in a given time
=speed/wavelength
• We discuss it so heavily bc its not easy to visit astrophysical objects (the sun, planets, other stars) and make direct measurement. We rely on remote sensing of EM radiation, which tells us the temp and comp
Term
What is a black body?
Definition
an object that radiates energy into space in a manner that is characteristic only of the
temperature of a radiator


o All BB’s radiate in more than one color
o Curve is eleated to T only
o Increasing T increases total intensity
o As t increases, peak moves to lower wavelength
o Wavelength of peak intensity related only to T (Wien’s law):
• Wavelength max=.29cm K/Tk
Term
Stephan-Boltzman's law
Definition
J=omega(T^4)
o J=total intensity
o T=temp
o Omega=5.67x10-8 Wxm^2xk^4 (constant)
Term
Type of spectra
Definition
• Continuous: black body radiation continuous
• Absorption: requires a cool object in front of a hot background (ex fraunhofer) discrete
• Emission: requires a hot object with a cool background (ex Bunsen) discrete
Term
Fraunhofer and Bunson?
Definition
Fraunhofer: solar black body cut by thousands of black bands
Bunson: put things on fire. Found that it produced lights in narrow bands with unique patterns
Term
Bohr Model of the atom:
Definition
• Wave properties of electrons are important
• An integer number of wavelengths fit in one orbit
• Electron distances and energies are discrete values
• 3 outer rights are energy states
• Electrons exist in orbits that are stable at specific separations from the nucleus
• The distance from the nucleus determines the energy of the electron (lower E is closer)
• The spacing is not even
Term
Radiative transfer?
Definition
Radiative transfer:
• Affects the temperature and composition of the atmosphere as we move from surface to space
• Scattering: photons are absorbed and reemitted in a different direction
• Photochemistry/photo-ionization: photons ionize atoms and molecules for dissociate molecules
• Fast particle: collisions cause an e- to jump energy levels and fall; a photon is emitted
• Airglow: recombination, chemical reactions, and cosmic rays
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