ASTR1345_FA23__Tue_10-17

pdf

School

University of Texas, Arlington *

*We aren’t endorsed by this school

Course

1315

Subject

Astronomy

Date

Apr 3, 2024

Type

pdf

Pages

32

Report

Uploaded by rozak999

ASTR 1345-003 Astronomy I, FALL 2023 MID-TERM EXAM II (10/12/2023) ANSWERS
1. (4 points) The word planet is derived from a Greek term meaning (a) bright object. (b) wandering object. (c) flat object. (d) large object.
2. (4 points) The intellectual foundation of science is (a) acceptance of theories based on strong faith. (b) rigorously testing observational data against theory. (c) carefully selecting data that are predicted by mathematical calculations. (d) collecting reliable data and sound skepticism.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
→ Scientific conclusions may change , but only through this rigorous procedure. Scientific Method & Progress One may improve data, but cannot fix data to fit theory. Theory should be fixed to fit data. “It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts” - Arthur Conan Doyle, The Adventures of Sherlock Holmes, 1892 Science is often driven by sound skepticism (rather than solid beliefs ), and may require technological innovations and time- consuming investigations by many scientists.
3. (4 points) A red photon has (a) a lower energy than a blue photon. (b) a shorter wavelength than a green photon. (c) a longer wavelength than an infrared photon. (d) a higher frequency than an X-ray photon. 4. (4 points) Which of the following sequences of electromagnetic wave is correct,
4. (4 points) Which of the following sequences of electromagnetic wave is correct, in order of decreasing energy of photons (with the highest energy first)? (a) visible, infrared, radio, X-ray, ultraviolet, Gamma-ray (b) radio, infrared, visible, ultraviolet, X-ray, Gamma-ray (c) X-ray, visible, Gamma-ray, ultraviolet, infrared, radio (d) Gamma-ray, X-ray, ultraviolet, visible, infrared, radio
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
5. (4 points) You have two types of laser-pointers with the red and green laser beam, respectively. What makes their light beam colors different? (a) The red laser-pointer produces beam of photons with a higher-energy. (b) The red laser-pointer produces beam of light waves with higher-frequency. (c) The red laser-pointer produces beam of light waves with a shorter-wavelength. (d) The red laser-pointer produces beam of photons with a lower-energy. (e) Colors of the laser beams are manufacturers' choice of how the light is painted inside of the device.
6. (4 points) If an astronaut landed on a planet of the same radius as the Earth but twice the mass, then the astronaut’s weight on the planet would be (a) 16 times her weight on the Earth. (b) 4 times her weight on the Earth. (c) the same as on Earth. (d) twice her weight on the Earth. The Law of Universal Gravitation
7. (4 points) Newton's law of gravitation applies (a) to all situations where two objects orbit each other solely under the influence of their mutual gravitational attraction. (b) only to situations similar to planets orbiting the Sun. (c) only close to the Sun and it is less accurate with increasing distance from the Sun. (d) to all planets' motion around the Sun, but not to Moon's motion around the Earth.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
8. (4 points) Copernicus’ heliocentric theory became preferable to the geocentric theory of Ptolemy, because (a) it explained the observed motions of the planets using complex system of circular motions, thus was considered more reliable than the geocentric theory. (b) it explained the observed planetary motions, but did so in a much simpler way. (c) it explained the retrograde motion, which the geocentric theory could not explain. (d) it explained the observed planetary motions, but did so much more accurately.
9. (4 points) Which of the following statements is/are correct? (a) Visible light takes up only a very small part of the total range of wavelengths in the electromagnetic spectrum. (b) Visible light is not part of the electromagnetic spectrum. (c) Visible light takes up the whole electromagnetic spectrum. (d) Visible light takes up most of the total range of wavelength in the electromagnetic spectrum.
10. (4 points) What is the difference between X-ray and radio waves? (a) X-rays and radio waves always come from different sources. (b) The wavelengths of X-rays and radio waves are very different. (c) The speeds of X-rays and radio waves in outer space are different. (d) Radio waves are always wavelike, whereas X-rays always behave like particles.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
11. (4 points) The speed of light in vacuum (or in outer space) is (a) infinite, traveling through anywhere in space instantaneously. (b) variable, depending on the speed of its radiating source. (c) fixed at 3 × 10 5 meters per second. (d) fixed at 3 × 10 8 meters per second. The speed of light in vacuum “ c is constant : c = 300,000 km/s = 3 × 10 8 m/s = 675,000,000 mi/hr
12. (4 points) Which of the following is the contribution of Kepler to our understanding of the Universe? (a) discovery of the Earth orbiting the Sun. (b) observation of the phases of Venus. (c) discovery of elliptical planetary orbits. (d) discovery of gravitational force.
13. (4 points) In building his heliocentric model, why did Copernicus conclude that the orbit of Venus is smaller than the orbit of the Earth around the Sun? (a) Because Venus can be seen near zenith at midnight. (b) Because Venus show a complete cycle of phases, like the Moon. (c) Because Venus always stays relatively close to the Sun in the sky. (d) Because Venus occasionally become brighter in the night sky. Sun Earth Venus
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
14. (4 points) In his heliocentric model, how did Copernicus explain Mars sometimes seen near the zenith at midnight? (a) Mars' orbit around the Sun is larger than the Earth's orbit around the Sun. (b) Mars orbit around the Sun is smaller than the Earth's orbit around the Sun. (c) Mars orbit around the Earth. (d) Mars orbits around the Sun, and its position can be in between Sun and Earth. Sun Earth Mars
15. (4 points) What is the significance of the discovery of Jupiter's moons to dispute the traditional geocentric model of the Universe? (a) They are small as seen from the Earth. (b) They are very far away from Jupiter. (c) They orbit around Jupiter. (d) They also orbit around the Earth.
16. (4 points) In which of the following parameters does a photon of visible light NOT differ from a photon of X-ray, in a vacuum? (a) speed (b) energy (c) frequency (d) wavelength
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
17. (4 points) Different colors of light are electromagnetic waves with different (a) wavelengths (b) amplitudes (c) speeds (d) intensities
18. (4 points) What is the relationship between light color and photon energy? (a) Energy decreases from red to white. (b) Energy increases from blue to red. (c) Energy decreases from blue to red. (d) Energy is independent of color.
19. (4 points) Nicolaus Copernicus was the first person to (a) use ellipses to describe the orbits of the planets. (b) use a telescope to observe the sky at night (c) develop a model for a Sun-centered solar system. (d) describe planetary orbits using the force of gravity.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
20. (4 points) Copernicus’ theory of the solar system was NOT correct in that (a) it could not explain the retrograde motion of planets. (b) it placed planetary motions in circular orbits. (c) it assumed that the planets move in elliptical orbits. (d) it placed planets on circular tracks, centers of which orbit around the Sun.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
21. (4 points) How is 1 AU (Astronomical Unit) defined? (a) The mass equal to that of the Sun (b) The distance traveled by light in 1 year (c) The mean distance between the Earth and the Moon (d) The mean distance between the Sun and the Earth
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
22. (4 points) What fundamental belief about the Universe was broken by the discovery of moons of Jupiter? (a) All heavenly bodies must move around the Sun. (b) The Sun must be at the center of the Universe. (c) All heavenly bodies must orbit around the Earth. (a) There must be only one moon. (d)
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
23. (4 points) Technological innovations may make a revolutionary progress in science. An excellent example in astronomy is Galileo's invention of (a) microscope. (b) astronomical telescope. (c) computer. (d) binocular.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
24. (4 points) The brightness of light from stars is determined by (a) the amplitude of the electromagnetic waves. (b) the energies of individual photons. (c) the frequencies of the electromagnetic waves. (d) the colors of individual photons. (e) the wavelengths of electromagnetic waves.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
Light: Particle-Wave Relation Brightness (or Intensity) of Light: Light brightness (intensity) amplitude Light brightness (intensity) number of photons Wave : Light brightness (intensity) frequency or wavelength Particle : Light brightness (intensity) photon energy → Light brightness (intensity) number of photons wave amplitude
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
25, (4 points) Suppose that a planet of the same mass as the Earth were orbiting the Sun at a distance of 10 AU. The gravitational force on this planet due to the Sun would be (a) 1/10 of the gravitational force the Sun exerts on the Earth. (b) 10 times the gravitational force the Sun exerts on the Earth. (c) 1/100 of the gravitational force the Sun exerts on the Earth. (d) 100 times the gravitational force the Sun exerts on the Earth. The Law of Universal Gravitation
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
Midterm Exam II Results
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
P A Average = 74.0 / 100 B C D Average = 75.5/100 A B P C D 42% class
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
P A Average = 74.0 / 100 B C D 42% class P A Average = 22.2 / 30 B C D One midterm exam (15%), Labs (25%), Final exam (30%)
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help
Midterm exam 2 grades will be posted in Canvas Announcements section. Check with your score in Canvas . If any discrepancy is found, contact with me immediately.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help