I.D.#
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Circle the
correct multiple choice answer.
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· Use space provided to answer non-numerical questions.
1. Ptolemy used the mathematical construct(s) of the ______ to explain retrograde motion.
(a) epicycle and deferrent
(b) egocentric model of the solar system
(c) heliocentric model of the solar system
(d) ellipse
(e) ferris wheel
2. How did Copernicus explain retrograde motion?
(a) He showed that it depended on which constellation the Earth happened to be headed toward in its motion around the Sun.
(b) He couldn’t explain it! Only the Ptolemaic model worked.
(c) He demonstrated that it could result from the Sun going around the Earth and the other planets going around the Sun.
(d) He showed that the Sun went around an immobile Earth and that retrograde motion could be explained as a visual effect that occurred when the planets passed close to the Sun.
(e) He showed that when, either a faster moving inferior planet passed by the Earth, or the Earth passed by a slowly moving superior planet, they would appear to moving “backwards” in the night sky relative to the background stars.
3. What observations did Tycho make that led him to conclude that the heavens were not “immutable”?
(a) In 1572, he tripped, his head striking the ground causing him to see stars where none had been before.
(b) He could not measure parallax for any stars.
(c) Using precision instruments, he could not measure any change in the relative positions of any stars throughout the course of a year.
(d) He could measure no parallax for a comet that he observed in 1577, indicating that it was located in the heavens, far from Earth like the stars, yet it was a “changeable object.”
(e) None of the above provided any evidence for the heliocentric model.
4. A comet with a period of 1000 years moves in a highly elongated, elliptical orbit about the Sun.
(a) What is the comet’s average distance from the Sun? ________________
(b) What is the farthest it gets from the Sun? (Hint: The closest it gets is a very small distance.) _________________
5. A line joining the Sun and an asteroid is found to sweep out an area of 4.9 AU 2 in 2005.
(a) How much area will it sweep out in 2006? ________________
(b) … over a period of 5 years? ________________
6. Why was the
discovery of
(a) It demonstrated that science played a role that was subservient to authoritative dogma when it came to trying to understand the natural world.
(b) It confirmed the heliocentric model.
(c) It
provided striking confirmation that
(d) It showed that scientists were very smart.
(e) It confirmed the theory of the origin of the solar system.
Chapter 5
7. Suppose that a certain FM radio station
decided to double its transmission frequency.
How would the wavelength of the radio waves emitted from this station
change? (Answer by stating the ratio of the new wavelength to the old one)
______________________
8. The bright star Antares in the constellation Scorpio (the Scorpion) emits
the greatest intensity of radiation at a wavelength (Lmax)
of 1210 nm.
(a)
What is
the surface temperature of the star? ________________
(b)
What
color is this star? ________________
9. An ultraviolet (uv) photon has a wavelength of 400 nm and an infrared
(ir) photon has a wavelength of 1200 nm.
(a)
Which
one has the most energy? ________________
(b)
… and by what factor? (State the ratio of the energies of the uv to the ir
photon.) ________________
10. The following is a sequence of ten elements (i through x), not by name, but by the number of protons in their nuclei:
(i) 1p (ii) 2p (iii) 6p (iv) 7p (v) 8p (vi) 14p (vii) 26p (viii) 53p (ix) 82p (x) 92p
Find the corresponding sequence of the matching names from the list below.
(a) (i) H (ii) D (iii) Li (iv) Be (v) B (vi) N (vii) Al (viii) Cr (ix) Fr (x) Nb
(b) (i) H (ii) He (iii) C (iv) N (v) O (vi) Si (vii) Fe (viii) I (ix) Pb (x) U
(c) (i) H (ii) C (iii) N (iv) O (v) Si (vi) Fe (vii) I (viii) Pb (ix) U (x) Pu
(d) (i) H (ii) He (iii) C (iv) N (v) O (vi) Si (vii) Fe (viii) I (ix) Pb (x) Pu
(e) (i) D (ii) He (iii) C (iv) N (v) O (vi) Si (vii) Fe (viii) I (ix) Pb (x) H
11. Can a hydrogen atom in the ground state absorb an H-alpha (Hα) photon? ______
(a) Yes … it can absorb a photon of any wavelength
(b) No … such an absorption would require the hydrogen atom to initially be in its first excited state (n = 2 state)
(c) Yes … the Hα photon is red and hydrogen atoms easily absorb red photons
(d) No … Hα photons can only be absorbed by helium atoms in the ground state
(e) No … Hα photons are only emitted by hydrogen atoms in the ground state
12. What was Neils
Bohr’s key hypothesis about the behavior of electrons in atoms that he
formulated to explain the discrete pattern of atomic spectra?
(a)
that the
nucleus of atoms consist of protons and neutrons
(b)
that the
orbits of electrons in atoms are ellipses with the nucleus at one of the foci
(c)
that
atoms can absorb and emit light
(d)
that, in
addition to the Balmer visible spectral series, there
must other unseen spectral series as well
(e)
that
electrons can orbit their nucleus in only certain discrete orbits at certain
specific levels of energy
13. Imagine a star A whose surface temperature is
2900 K and whose diameter is the same as that of a Sun-like star B. Suppose that both stars were located at the
same distance from Earth.
(a)
Which
would be the brighter? ________________
(b)
… by what factor?
(State the ratio of the brightness, or luminosity, of star A to star B.)
________________
14. Draw a diagram of ________.
(a)
a
refracting telescope
(b)
a
Newtonian focus telescope
(c)
a Cassegrain focus telescope
(d)
a prime
focus telescope
15. Which of the following telescopes suffers
from the unfixable defect of chromatic aberration?
(a)
a
refracting telescope
(b)
a
Newtonian focus telescope
(c)
a Cassegrain focus telescope
(d)
a prime
focus telescope
(e)
a Coude focus telescope
16. A telescope with a large objective (primary
mirror) has a primary advantage of ________ over that of a small one.
(a)
larger
magnification
(b)
reduced
spherical aberration
(c)
larger
light gathering power
(d)
reduced
chromatic aberration
(e)
ease of
supporting it with an equatorial mount
17. Adaptive optics
refers to the ability of a telescope to _______.
(a)
automatically
change eyepieces in order to change magnification.
(b)
automatically
switch from low resolution to high resolution to study a smaller part of a
large object.
(c)
suddenly protect
its optics from damage from solar flares.
(d)
quickly change the
shape of its primary mirror to compensate for poor seeing due to atmospheric
turbulence.
(e)
quickly change its
focus in order to maintain clarity of view on objects receding from us at very
high speeds.
18. Astronomers must
deploy telescopes in space to study the heavens at X-ray and gamma-ray
wavelengths because X-rays and gamma rays ______.
(a)
do not
penetrate the Earth’s atmosphere
(b)
generate
showers of cosmic ray particles in the Earth’s atmosphere which would obscure
the view of an object
(c)
are
harmful to Earth-bound observers
(d)
require
telescopes that must be cooled to almost absolute zero temperature
(e)
require the
use of special radioactive material, which would be dangerous on Earth, to
power their telescopes
19. The observing cage in which an astronomer
sits at the prime focus of the 5-m telescope on
________________
20. The Russian
Space Agency plans to place a radio telescope into an even higher orbit than
the Japanese HALCA telescope. Using this telescope in concert with the VLBA, baselines as long as
77,000 km may be obtainable.
Astronomers want to use this combination to study radio emission from
distant objects called quasars at a frequency of 1665 MHz.
(a)
What is
the wavelength corresponding to the frequency of this emission? ________________
(b)
What is
its angular resolution, taking the baseline to be the effective diameter of
this radio-telescope array? ________________