Astronomy I Exam I Sample Name: Read each question carefully, and choose the best answer.

Transcription

1 Name: Read each question carefully, and choose the best answer. 1. During a night in Schuylkill Haven, most of the stars in the sky (A) are stationary through the night. (B) the actual motion depends upon the season. (C) rise in the west and set in the east. (D) rise in the east and set in the west. 2. A set of numbers used to locate something is called (A) a reference plane. (B) a Great Circle. (C) a zero point. (D) a coordinate system. 3. On the celestial sphere, the circle which is located 90 degrees from the zenith is the (A) horizon. (B) zenith. (C) equator. (D) azimuth. 4. The angular distance of an object from the horizon is its (A) declination. (B) altitude. (C) latitude. (D) right ascension. 5. A finger, held at arm's length, fills an angle of about (A) 10 degrees (B) 2 degrees (C) ½ degree (D) a minute 6. The angular size of the Sun and Moon are both about (A) ½ of a great circle. (B) ½ of an angstrom. (C) ½ a second. (D) ½ a degree. 7. The north-south line that passes directly overhead is the (A) horizon. (B) equator. (C) meridian. (D) azimuth. 1

2 8. As seen from Schuylkill Haven, Circumpolar stars (A) are located in the region of the sky centered about Polaris. (B) never set. (C) move in a counterclockwise motion in the sky. (D) all of the above. 9. The diurnal motion of an object in the sky is its (A) motion over one year relative to the celestial sphere (B) temporary reversal of its usual motion (C) daily motion relative to the horizon (D) ecliptic 10. How long does it take the sun to make one complete circuit of the ecliptic? (A) day. (B) week. (C) month. (D) year. 11. The ecliptic is the (A) projection of the Earth s equator on the celestial sphere. (B) plane of the Moon s orbit. (C) apparent path of the Sun on the celestial sphere. (D) projection of the north celestial pole on the zodiac. 12. The objects which exhibit retrograde motion, as seen from the earth, are (A) the moon. (B) the sun. (C) the planets. (D) all of the above. 13. In which of the following circumstances is it possible to observe the full moon? (A) setting at sunrise (B) rising at noon (C) high in the sky at dawn (D) setting at midnight 14. When does the most northernly sunrise occur? (A) autumnal equinox (B) vernal equinox (C) summer solstice (D) winter solstice 15. Which of the following best describes the motion of the Moon? (A) toward the east with respect to the stars, westward across the sky. (B) toward the east with respect to the stars, eastward across the sky. (C) toward the west with respect to the stars, westward across the sky. (D) toward the west with respect to the stars, eastward across the sky. 2

3 16. Local noon corresponds to the time when the Sun is on the (A) Zenith. (B) Meridian. (C) Nadir. (D) Ecliptic. 17. As viewed from Schuylkill Haven, how does the planet Venus move with respect to the stars? (A) always eastward. (B) always westward (C) it stays in the same place at all times. (D) mostly eastward, but sometimes westward. 18. Which of the following was not a product of Babylonian Astronomy? (A) Accurate tables of planetary positions. (B) recognition of variations in the planetary cycles. (C) arithmetic methods of predicting planetary positions. (D) a detailed model of the solar system. 19. A shift in the direction of an object caused by a change in the position of an observer is called (A) precession. (B) the Coriolis effect. (C) parallax. (D) epicycle motion. 20. How did Eratosthenes determine the size of the Earth? (A) by observing the lengths of shadows at different locations. (B) by observing the size of the Earth's shadow during eclipses. (C) by determining the density and mass of the Earth. (D) by measuring the parallax of the moon. 21. Ptolemy used epicycles (illustrated at right) to explain (A) the equation of time. (B) circumpolar motion. (C) retrograde motion. (D) eclipses. 22. What was the significance of Galileo's discovery that Venus shows all phases from new to full? (A) it showed that Venus has a thick atmosphere. (B) it proved that Galileo's telescope worked well. (C) in Ptolemy's geocentric model, only certain phases were possible. (D) the observation showed that Venus does not have a satellite. 23. Why did Tycho Brahe reject Copernicus's model of the solar system? (A) He could not detect stellar parallax (B) He could not detect retrograde motion for Mars (C) The ellipse had not been discovered yet (D) Tycho found mistakes in Copernicus's calculations 3

4 (24-27) Match the element of the Copernican model below with its observation consequence: A. Earth's motion around object. B. Motion of object around earth. C. Object overtakes Earth. D. Earth rotates. 24. The moon's monthly motion 25. Venus undergoing retrograde motion 26. The sun moves west to east along the ecliptic 27. The sun moves east to west daily 28. Which of the following best completes this sentence: When tested against the observed motion of the planets, (A) Ptolemy s model was least accurate, Kepler s was more accurate and Copernicus s was most accurate. (B) Ptolemy s model was least accurate, Copernicus s was more accurate and Kepler s was most accurate. (C) Ptolemy s model was most accurate, Copernicus s was less accurate and Kepler s was least accurate. (D) Ptolemy s model and Copernicus s were about equally accurate, and Kepler s was more accurate 29. Where did Kepler get the data used to create his 3 laws of planetary motion? (A) Observations of the Ancient Babylonians. (B) His own telescopic observations. (C) Tycho Brahe. (D) He made the data up. 30. What object is located at one focus of the orbit of the planet Mars? (A) The Sun (B) the Earth (C) Mars (D) Jupiter 31. According to Kepler's Laws, a planet which is closer to the Sun than the Earth (A) will take less than a year to orbit the Sun. (B) will take more than a year to orbit the Sun. (C) will have a more elliptical orbit around the Sun than Earth's orbit. (D) will eventually begin orbiting the Earth. 32. Newton's great breakthrough in how he viewed the cosmos was that he (A) viewed gravity as a mysterious force between masses. (B) thought that natural motion was distinct from forced motion. (C) determined that the universe as infinite in extent. (D) applied the same physical laws in the sky and on Earth. 4

5 33. For an object to accelerate it must (A) change its speed (B) change its direction of motion (C) change its speed and direction of motion. (D) change its speed or direction of motion 34. The force required to keep an object in a circular orbit is directed (A) in the direction opposite to that in which the object is moving (B) directly away from the center of the circle (C) in the direction in which the object is moving (D) toward the center of the circle 35. If the distance between two objects is decreased, the force of gravity they exert on each other will (A) remain the same (B) increase (C) decrease (D) vanish 36. Newton's theory of Universal Gravitation, combined with mechanics (A) was important because it described both earthly and cosmic phenomena using the same principles. (B) explained falling objects and projectile motion. (C) explained Kepler's Laws. (D) all of the above. 37. During Rip tides (which are the strongest tides) (A) the Earth, moon, and Sun are all in alignment (B) the moon, Earth, and Sun are all at right angles (C) only the Earth is deformed, not the moon (D) day and night are the same interval of time 38. Kinetic energy (A) is the energy associated with the gravitational attraction of an object by another object (B) is the same thing as electric charge (C) is the energy associated with the motion of an object (D) is responsible for the retrograde motion of stars 39. A particle of light is a (A) graviton (B) photon (C) angstrom (D) neutrino 40. Which form of electromagnetic waves (or photons) has the least energy? (A) the wave with the smallest frequency. (B) the wave with the largest frequency. (C) frequency and energy have nothing to do with each other. (D) trick question, photons exist only in the minds of the writers of Star Trek. 5

6 41. Which of the following principles from Optics are relevant to telescopes? (A) Refraction (light rays bend at interfaces). (B) Reflection (light rays bounce at surfaces). (C) Diffraction (light waves bend around corners). (D) all of the above 42. In the laboratory, an atom emits a spectral line at a wavelength of a particular color (wavelength). In the spectrum of a star, the same spectral line is found to have a wavelength which is shorter (that is, the wavelength is "bluer"). What can be said about the star? (A) It is hotter than the Sun. (B) It is moving toward the Earth. (C) It is moving away from the Earth (D) It contains elements that are not found on Earth. 43. What is the primary reason that radio astronomers use arrays of telescopes to observe celestial objects? (A) to obtain great light gathering power. (B) to obtain great magnification. (C) to obtain high angular resolution. (D) to avoid disturbances in the Earth's atmosphere. 44. The energy transport process in which heat is transferred by electromagnetic waves (like infrared light): (A) radiative transfer (B) convection (C) conduction (D) fusion 45. Which of the following planets is most likely to retain a thick atmosphere? (A) a planet with a hot atmosphere, low gravity. (B) a planet with a hot atmosphere, high gravity. (C) a planet with a cool atmosphere, low gravity (D) a planet with a cool atmosphere, high gravity. 46. What happens to the electromagnetic radiation emitted by a blackbody if the blackbody gets hotter? (A) It would get redder and dimmer (B) It would get redder and brighter (C) It would get bluer and dimmer (D) It would get bluer and brighter 47. In what process does split to form two (or more) fragments while releasing energy? (A) fission (B) fusion (C) radioactivity (D) convection 6

7 48. In an atmosphere composed of a mixture of gases at a particular temperature, the molecules that move fastest are those that have (A) the biggest diameter (B) the largest chemical formula (C) the most mass (D) the least mass 49. The most abundant elements in the solar system are (A) Carbon and Water. (B) Hydrogen and Iron. (C) Iron and Nickel. (D) Hydrogen and Helium. 50. The half-life of a particular isotope of potassium is 1.3 billion years. After 2.6 billion years, how much of the original amount of that isotope remains? (A) Half (B) None (C) One-fourth (D) All of it 7