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1
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- Question 1 (1 point) In a
lava lamp, heat is transported by blobs of hot wax moving up when they
are hot and down when they are cooler. What type of heat transport is
this?
a. Conduction b. Radiation c. Convection d.
No heat is transported.
- Question 2 (1
point) You're the captain of a Bird of Prey during the Klingon Civil
War. You're being pursued by a dishonorable traitor who deserves to die.
Directing your ship to the flare star you skim its surface, dodging
disruptor fire the whole time. Your sensors pick up a building solar
flare, as powerful as anything produced on Earth's sun. If the pursuing
ship's shields can absorb the power of a thousand hydrogen bombs, can it
survive this flare? (This information IS in your textbook! Check out the
two-page spread.)
- a. I'm peaceful and live according to the non-violent principles of
Ghandi!
- b. Yes, I must find another way to destroy my pursuer.
- c. No, he will die like the dog he is! I just hope I can escape it
myself, but if I do not they will write an epic poem about my deeds.
- Question 3 (1
point) Most of the light we see coming from the sun originates in
the
a.chromosphere
b.photosphere c.corona d.sunspots e.magnetic field
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2
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- Question 4 (1 point) The key difference between atoms of two
different chemical elements is their number of
a.Electrons
b.Protons c.Neutrons
- Question 5 (1 point) The neutral atom of the most common
form of hydrogen consists of
- a.one proton and one neutron.
- b.one proton.
- c.one proton, one neutron, and one electron.
- d.one proton and one electron.
- e.an isotope and an ion.
- Question 6 (1
point) Two neutral atoms of the same element but of different isotopes
contain the same number of
- a. Electrons, Protons, and Neutrons
- b. Electrons and Protons but not Neutrons
- c. Electrons and Neutrons but not Protons
- d. Neutrons and Protons but not Electrons
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3
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- Question 7 (1 point) The sun produces energy by converting
mass into energy via a fusion process. How much energy is produced when
the sun converts 1 kg of mass into energy? Also note that when checking
units the unit of energy called a "Joule" is shorthand for a
"kg m2/s2".
a. 6 x 1016 J b. 9 x 108
J c. 6 x 1016 J d. 3 x 1016
J e. 9 x 1016 J
- E = mc2. Mass = 1
kg, c = 3x108 m/s.
So E= 1kg x (3x108 m/s)2
- So that’s jut 9x1016 J, right?
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4
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- Question 8 (1 point) How much energy is produced when the
sun converts 1 kg of hydrogen into helium? Note that this is different
than a problem which asks how much energy is produced when the sun
converts 1 kg of mass into energy. When hydrogen is converted to helium,
only a small fraction of the mass is "lost" and converted to
energy.
a. 1.2 x
1012 J b. 6.4 x 1014 J
c. 2.8 x 1015 J d. 9.0 x 1016
J
- From class notes: Compare mass of four 1H to mass of one 4He
- 6.693 ´ 10-27
kg - 6.645 ´ 10-27 kg = 0.048 ´ 10-27 kg
drop in mass
- E = mc2 = 0.048 ´ 10-27 kg ´ (3 ´ 108 m/s)2 = 0.43 ´ 10-11 kg m2/s2
= 0.43 ´ 10-11 J
- So 4.3 ´ 10-12
J of energy released for every He made.
- How many Hydrogen atoms in a kg?
Just 1 kg/1.673x10-27 = 5.976x1026
- Divide this by 4 (since 4 hydrogens = 1 He). Multiply this by energy for each
He produced = 5.976x1026 x 4.3 ´ 10-12 J = 6.4 x 1014 J
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5
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- Question 9 (1
point) If a sunspot has a temperature of 4200 K and the solar surface
has a temperature of 5800 K, how many times brighter is the surface
compared with the sunspot? (Hint: Use the Stefan-Boltzmann law.)
a.It isn't brighter -- it is fainter! b.About 1.4 times
brighter. c.About 3.6 times brighter. d.About 5.6 times
brighter.
- Sunspot brightness, use E = σT4
- (T1/T2)4 = (5800/4200)4 = 3.6 times brighter
- Question 10 (1 point)
Fusion of very light elements to make heavier ones releases energy, as
does fission of very heavy elements to make lighter ones. The most
"energetically favorable" and stable element from which
neither fission nor fusion can release energy is
a.Hydrogen b.Helium c.Carbon d.Iron
e.Uranium
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Notes