Astronomy 10
Fall 2007
Midterm 3, In-class activity 22, 11/7-14 CPS
(Posted 071121)
1. (Q7.1)
b = bb = 3.0 points
2. (Q7.1)
e = bb = 3.0 points
3. (Q8.5)
d = dd = 3.0 points
4. (Q8.4)
e = dd = 3.0 points
5. (Q9.5)
b = aa = 3.0 points
6. (M3.1)
a = cc = 3.0 points
7. (M3.2)
e = ee = 3.0 points
8. (M3.3)
d = dd = 3.0 points
9. (M3.4)
d = aa = 3.0 points
10. (M3.5)
d = aa = 3.0 points
=====
(For the short-answer questions, refer to the grading comments below for
specific details as to what these letters mean.)
=====
11. (Q8.3)
p = 15/15: Correct. Wien's law says that Object X (peak intensity at a shorter
wavelength) must be hotter than Object Y. The Stefan-Boltzmann law says that
luminosity (related to the intensity of the peak) is proportional to size and
temperature^4. Since Object X is hotter, in order for it to be _less_ luminous
than Object Y is for Object X to be much smaller than Object Y. May only
implicitly utilize Wien's law in discussion.
r = 12/15: Nearly correct (explanation weak, unclear or only nearly complete);
includes extraneous/tangential information; or has minor errors.
t = 9/15: Contains right ideas, but discussion is unclear/incomplete or contains
major errors. At least understands the Stefan-Boltzmann law.
v = 6/15: Limited relevant discussion of supporting evidence of at least some
merit, but in an inconsistent or unclear manner.
x = 3/15: Implementation/application of ideas, but credit given for effort
rather than merit.
y = 1.5/15: Irrelevant discussion/effectively blank.
z = 0/15: Blank.
=====
12. (Q9.5)
p = 15/15: Correct. White dwarfs are the end product of medium mass stars.
Supergiants are near the end of massive stars. It will take longer for a medium
mass protostar to reach the main sequence, end its main sequence lifetime, go
through its giant phase to become a white dwarf than a massive protostar to go
through similar stages. Thus stars in a star cluster, which started at the same
time, cannot have white dwarfs and supergiants existing at a same later time.
r = 12/15: Nearly correct (explanation weak, unclear or only nearly complete);
includes extraneous/tangential information; or has minor errors. Understands
that evolution times (protostar to main sequence, main sequence lifetime, main
sequence to end stage) are inversely proportional to mass, but discussion of
these stages has minor omissions or errors. Or understands evolutionary
sequence that results in these end stages, but discussion of evolutionary times
has minor omissions or errors.
t = 9/15: Contains right ideas, but discussion is unclear/incomplete or contains
major errors. As (r), but discussion of evolutionary stages, or times is
problematic.
v = 6/15: Limited relevant discussion of supporting evidence of at least some
merit, but in an inconsistent or unclear manner.
x = 3/15: Implementation/application of ideas, but credit given for effort
rather than merit.
y = 1.5/15: Irrelevant discussion/effectively blank.
z = 0/15: Blank.
=====
13. (M3.1)
p = 15/15: Correct. In its giant phase, heavier and heavier elements are fused
until the core becomes carbon, but temperatures and pressures are unable to
continue heavier fusion. Without an energy source to balance gravity, the giant
lifetime of the medium mass star ends as the core gravitationally contracts into
a white dwarf, while giving off enough energy to disperse its outer layers as a
planetary nebula.
r = 12/15: Nearly correct (explanation weak, unclear or only nearly complete);
includes extraneous/tangential information; or has minor errors. Understands
how the giant lifetime of a medium mass star occurs, but does not completely
explains _why_ it must end.
t = 9/15: Contains right ideas, but discussion is unclear/incomplete or contains
major errors. May confuse discussion with that of supergiants and type II
supernovae, but at least understands the importance of no more energy being
released from fusion.
v = 6/15: Limited relevant discussion of supporting evidence of at least some
merit, but in an inconsistent or unclear manner.
x = 3/15: Implementation/application of ideas, but credit given for effort
rather than merit.
y = 1.5/15: Irrelevant discussion/effectively blank.
z = 0/15: Blank.
=====
Midterm 3 average = 48.2/75
PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 MT3 A22 CPS
0115 bb bb dd dd aa cc dd dd aa aa t p p 66 0 2.4
0417 b e d e b a e d d d r p p 72 3.0 9.3
0523 c d d e a e e d d d t x t 39 3.0 9.3
0605 bb bb cc bb aa cc ee cc ee aa r t r 51 3.0 9.3
1000 b e d e b a e c d d r v t 54 3.0 9.3
1022 a e e e b c e e d d v x t 36 3.0 9.3
1256 bb dd dd dd cc ee ee dd dd aa t p p 57 3.0 9.3
1313 0 2.4
1315 0 2.4
1369 bb bb dd dd aa cc ee ee ee aa v p t 54 3.0 9.3
1624 b a e d b c b c c a p x t 33 3.0 9.3
1666 cc bb aa dd aa ee ee cc ee aa t r t 45 3.0 8.7
1831 b e d e b a d e b d v r t 48 3.0 9.3
1938 bb bb aa dd aa cc ee cc aa aa t t v 48 3.0 9.3
1950 b d d e e e e d e d t r t 48 3.0 2.4
1985 c e d c b e e c e e p t t 45 3.0 9.3
1987 bb bb dd dd aa cc ee ee aa bb p x v 48 3.0 8.4
2115 bb dd dd bb aa cc bb bb dd aa p r t 51 3.0 9.3
2189 b d b b b e d d c d t v x 30 0 2.4
2251 cc bb dd cc aa cc ee cc ee ee p p t 54 3.0 9.0
2360 b e e e b a d c d c v v t 39 3.0 9.3
2389 b d d e b a e c d d t p r 60 3.0 9.3
2778 0 2.4
2987 0 0
3428 bb bb dd dd ee cc aa cc ee bb t x p 42 0 2.4
4040 bb dd dd dd aa cc ee dd aa aa p p p 72 3.0 9.3
4197 3.0 9.3
4400 cc dd dd dd aa ee ee cc dd aa v x x 27 3.0 9.3
4402 b e e e b c e e d a p r p 60 3.0 9.3
4525 bb bb aa dd aa cc ee ee aa ee t t r 51 3.0 9.3
4545 3.0 2.4
4832 bb bb bb dd aa cc ee dd aa cc p r p 66 3.0 9.3
4888 cc bb dd dd aa cc ee dd aa aa p v r 60 3.0 9.3
5150 b a d c b c e c d e v t t 39 3.0 8.7
5288 bb bb dd dd aa cc ee dd aa bb v y p 49.5 0 2.4
5450 z bb dd dd dd bb ee bb aa aa p t t 51 3.0 8.7
6616 b e d d b e b d d d t p r 57 3.0 9.3
6890 bb cc aa cc bb ee ee dd aa aa t x p 42 3.0
7276 dd bb dd dd dd cc ee cc dd aa p r t 54 3.0 9.3
7635 b e a e b c e c z c p x t 42 3.0 9.3
7676 3.0 9.3
7823 bb bb ee dd aa dd ee ee aa bb t r r 51 3.0 9.3
7887 b e d b b a e d d d r r r 63 2.6 8.7
8141 c a d a c a d e b a z x x 12 0 2.4
8185 dd dd ee dd aa cc ee dd aa aa v r p 54 3.0 9.3
8556 b e e e b e b a b e p v v 39 3.0 9.3
8686 b e e e b c a d d e t v v 39 2.6 9.3
9876 z c a a e c e c d d v x r 30 3.0 8.7
9965 d e b d b e e e d e p t t 45 3.0 6.9
NOTES:
*Do not forget your Astr 10 PIN number!
*The cumulative class CPS review score was 85%, which means double
participation bonus for the review.
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