2. the Angular Diameter of the Moon Is: A. a Degree, B. 1 Degree, C. 3 Degrees, D. 5 Degrees

ASTRONOMY 40---HOMEWORK I (New)

1. Pluto is considered to be a planet. (T or F)

2. The angular diameter of the moon is: A. ½ a degree, B. 1 degree, C. 3 degrees, D. 5 degrees.

3. How many minutes of arc in a degree? A. 10, B. 60, C. 360, D. 3600.

4. A gigagram, if there were such a thing, would be how many grams? A. a thousand, B. a million, C. a billion, D. a trillion.

5. A parsec is the distance at which the earth and sun would appear to be one arc- second apart. (T or F)

6. A new planet is discovered and has an angular diameter of 1.5 arcsec. By bouncing radar off it and timing is return we find it to be 250,000,000 km away. What is the diameter of this planet (rounded off)? A. 12.6 km, B. 540 km, C. 1820 km, D. 4850 km, E. 10,260 km.

7. The Astronomical Unit (AU) is useful for denoting distances within the solar system. (T or F)

8. Because light takes appreciable time to get to us from distant objects, a telescope lets us look into the past. (T or F)

9. If the north star is 40 degrees from the horizon (as it roughly is in Fairfield, California), roughly how many fists with the arm extended could be placed over that angular distance side by side? A. 2, B. 4, C. 8, D. 10.

10. A hypothesis has always been well tested by observations and/or experiments. (T or F)

11. Naked eye astronomy is how well you see the sky without glasses or contacts. (T or F)

12. Stars in a constellation are more or less all at the same distance. (T or F)

13. Stars rise in the east and set in the west, just like the sun, but 4 minutes/day faster. (T or F)

14. The term diurnal means A. hourly, B. daily, C. weekly, D. with respect to the stars.

15. The position of the constellation Auriga at 9 pm will have shifted about 14 degrees toward the west in 2 weeks. (T or F)

16. The north star can be located by looking above the end of the cup of the Big Dipper, and when away from the light of the cities, at the end of A. the constellation Cassiopeia, B. Draco, the dragon, C. the handle of the Little Dipper. 2

17. The three stars in the Belt of Orion point to the brightest star in the sky, which is A. Betelgeuse, B. Alpha Centauri, C. Dubhe, D. Sirius.

18. Some Landmarks on the Celestial Sphere are projections of those on earth, like the Celestial Equator and the North and South Celestial Poles. (T or F)

19. Your latitude and the angular height of the celestial sphere above the horizon are identical. (T or F)

20. The earth's axis wobbles once as it orbits the sun once. (T or F)

21. The time it takes for a planet or moon to go from one opposition to the sun to another is called what period? A. sidereal, B. synodic, C. orbital, D. rotational.

22. Copernicus came very close to calculating numbers close to the modern values for average distances from the sun. (T or F)

23. Which planet has the longest orbital period with respect to the stars? A. Mars, B. Jupiter, C. Saturn, D. Neptune. 24. The eccentricity, e, of planetary orbits increases as the orbits become more circular. (T or F) 25. A planet's semimajor axis is equal to is average distance from the sun (research this online--Google?). (T or F) 26. The moon appears roughly the same size throughout its cycle of phases, but which planet did Galileo observe to change size through its phases? (therefore indicating it doesn't not orbit the earth, but rather the sun.) A. Jupiter, B. Mars, C. Venus, D. Neptune. 27. Isaac Newton's 3 Laws of Motion apply to things on earth, but not in space. (T or F) 28. The S. I. unit of force or weight is the A. kilogram, B. pound, C. Newton, D. dyne. 29. An object coming from outside the solar system, then leaving again moves in what trajectory (path)? (Do research online.) A. ellipse, B. parabola, C. hyperbola, D. circle. 30. Even galaxies can be distorted by tidal forces. (T or F) 31. Galileo tried to measure the speed of light by communicating by his lantern with another one held by an assistant on a distant hilltop. Why would you guess he realized he had failed? A. his assistant’s reaction time exceeded light travel time, B. fog, C. he didn’t have a clock accurate enough.

32. If the wavelength of light is greater, the frequency is A. lower, B. higher, C. the same. 33. A wavelength of 483 nanometers would be in what range? A. infrared, B. ultraviolet, C. gamma rays, D. visible. 34. A wavelength of a centimeter would be in what range? A. visible, B. ultraviolet, C. microwave, D. infrared. 3

35. To get Celsius from Kelvin temperature we subtract, how many degrees? (Check by Googling, if necessary.) A. 32, B. 273, C. 1258. 36. A perfect absorber and emitter of electromagnetic radiation at all wavelengths is called A. an emitatron, B. a photon, C. a blackbody, D. a fluke. 37. From Wien's Law, if we know the peak wavelength of a black body (like the sun), we can get it's A. size, B. surface temperature, C. emission depth, D. age. 38. The Stephan-Boltzmann Law says that the surface flux on a black body like the sun, changes how as the temperature increases? A. rapidly increases, B. slowly increases, C. rapidly decreases, D. slowly decreases. 39. The greatest number of watts a solar panel of 2 square meters could receive from the sun is A. 1370 watts, B. 2740 watts, C. 150 watts. 40. Light comes in bundles or quanta of energy we call A. quantodes, B. photons, C. gravitrons. 41. One of the greatest advantages of a telescope is that it can gather more light than the naked eye can, allowing it to pick up fainter, more distant objects in the sky. (T or F) 42. The speed of light in air and glass is the same. (T or F) 43. Light exits a flat pane of glass in the same direction it entered. (T or F) 44. The objective (big) lens in a refracting telescope is located roughly its focal length plus what distance away from the eyepiece lens? A. the diameter of the eyepiece, B. the focal length of the eyepiece, C. the magnification expressed in cm. 45. If I double the diameter of the objective mirror or lens of a telescope, what happens to the light gathering power (resulting in what ability to see faint objects)? A. it doubles, B. it quadruples, C. it is halved. 46. Lenses suffer from chromatic aberration, but mirrors do not. (T or F) 47. There are certain wavelengths of light that are blocked by an objective lens, but not by an objective mirror. (T or F) 48. In a telescope with a Newtonian focus, the observer is looking in the direction of the object viewed. (T or F) 49. Inexpensive telescopes are made with spherical mirrors, but large ones have distorted images because of A. chromatic aberration, B. spherical aberration, C. absorption of certain wavelengths. 50. One reason to place a telescope on a tall mountain is to avoid large amounts of A. spherical aberration, B. atmospheric turbulence, C. solar interference. 4