Exam # 1 Thu 10/06/2010 Astronomy 100/190Y Exploring the Universe Fall 11 Instructor: Daniela Calzetti

Transcription

1 Exam # 1 Thu 10/06/2010 Astronomy 100/190Y Exploring the Universe Fall 11 Instructor: Daniela Calzetti INSTRUCTIONS: Please, use the `bubble sheet and a pencil # 2 to answer the exam questions, by marking the appropriate bubble for each question. Write your last and first name and Student ID on the `bubble sheet, and mark them in the bubbles. Use of textbook and class notes is allowed. There are a total of 39 questions. 1. How many arcseconds there are in 1 arcminute? A. 6 B. 24 C. 60 D. 360 E How is in relation to 1x10-5? A. larger B. the same C. smaller 3. What phase would the Earth appear to be in, if you were standing on the Moon at New Moon? A. Waxing gibbous B. Crescent C. Full D. New E. Only the Moon can show phases. 4. Friends tell you that they saw the constellation Orion high in the sky at 4 a.m. this morning. You are not interested in getting out of bed so early. How many months will you have to wait until Orion is in the same place of the sky at midnight? A. One month B. Two months C. Three months D. Four months E. Ten months 5. From the largest to the smallest, what is the correct order of the following distances? (ly=light year; AU=Astronomical Unit) A. 1 mm, 1 m, 1 ly, 1 AU B. 1 AU, 1 ly, 1 m, 1 mm C. 1 mm, 1 m, 1 AU, 1 ly D. 1 ly, 1 AU, 1 mm, 1 m E. 1 ly, 1 AU, 1 m, 1 mm

2 6. Gravity: A. is the attraction between all objects with mass B. is the result of the pressure of the atmosphere on us C. occurs between objects that are touching each other D. is the force larger objects exert on smaller ones E. is caused only by planets and the Sun 7. Low tide during New Moon occurs at: A. Midnight B. 6 am and 6 pm C. 6 pm D. Midnight and Noon E. Noon 8. If the Moon were two times closer to the Earth, the gravitational force between them would be: A. 4 times weaker than now B. 2 times weaker than now C. the same as now D. twice stronger than now E. 4 times stronger than now 9. The Sun appears in front of a different constellation each month due to: A. the Sun s motion around the center of the Mikly Way Galaxy B. the Earth s orbital motion around the Sun C. the precession of the rotation axis of the Earth D. the Earth s rotation on its axis E. the Moon s orbit around the Earth 10. What phase needs the Moon to be in, for a solar eclipse to occur? A. New B. First Quarter C. Full D. Third Quarter E. Gibbous Waning 11. Newton concluded that some force had to act on the Moon because A. a force is needed to keep the Moon in motion B. a force is needed to pull the Moon outward C. the Moon moved at a constant velocity D. a force is needed to pull the Moon away from a straight-line motion E. all of the above

3 12. A bunch of apples on a scale that measures their weight would read (relative to the weight you measure at home): A. less if it were accelerating upward in an elevator B. zero if it were free-falling from a cliff C. more if it were located on the Moon D. less if it were sitting in a stationary rocket on a launch pad at sea level. E. less if it were on the surface of the Sun (assuming it does not melt!) 13. Each day, from a point of Earth north of the equator, most stars appear to A. remain stationary overhead B. rise in the west and set in the east C. rise in the east and set in the west D. move to the south E. move to the north 14. If you measure the angle between zenith and Polaris to be 35 degrees, you must be located at: A. 35 degrees latitude North B. 55 degrees latitude North C. 0 degrees latitude D. 55 degrees latitude South E. 35 degrees latitude South 15. A cart of mass M is moving at constant speed v. Suddenly a weight of mass m drops on the cart. The momentum of the cart: A. increases B. decreases C. stays the same 16. Newton s Second Law expresses the fact that: applying a force to an object is likely to cause it to: A. move at constant velocity in proportion to its mass B. accelerate in a manner independent of its mass C. change the direction of motion in proportion to its mass D. move at a constant velocity independent of its mass E. accelerate in proportion to its mass 17. The third quarter Moon sets: A. at sunrise B. at about noon C. at sunset D. at about midnight E. every calendar month

4 18. If the Sun were a grapefruit in this room, the nearest star (Proxima Centauri) would be: A. a soccer ball in Hawaii. B. another grapefruit on the West Coast. C. another grapefruit on the other side of campus. D. a peppercorn about 100 m away. E. a poppyseed about 15 m away. 19. The plane which contains the orbit of the Earth as it moves around the Sun is called A. zodiac B. ecliptic C. precession D. celestial equator E. equinox 20. In which situation would the tides be strongest: A. the Moon and the Sun are aligned in the same direction B. the Moon and the Sun are at 90 degrees C. the Moon and the Sun are at 45 degrees D. the Sun and all the other planets are opposite to each other respect to the Earth E. tides always have the same intensity 21. If the Sun shrunk to the size of the Earth, more than 100 times smaller, in radius, it would spin: A. 100 times slower B. (100) 2 times slower C. at the same rate, since it has the same mass D. (100) 2 times faster E. 100 times faster 22. A cannon ball is fired against a wall, and gets lodged into the wall. This means that its kinetic energy has been transformed into: A. potential energy B. mechanical energy C. thermal energy D. chemical energy E. the energy has been lost 23. Newton s Second Law expresses the fact that an acceleration decreases if the mass of a body increases, a=f/m. If you drop a large, massive stone and a small, light stone from a tower, the massive stone will reach the ground before the lighter stone (assume there is no air). A. true B. false

5 24. A lunar eclipse can only occur when the Moon is: A. Waxing B. Waning C. Full D. New E. Blue 25. Each day the Moon raises about: A. the same time B. it depends on the year C. it depends on the season D. about an hour earlier E. about an hour later 26. Due to tides raised on the Earth by the Moon, the Moon is gradually moving FURTHER away from the Earth. The average distance between the Earth and the Sun remains constant with time. How will solar eclipses be different in a distant future as a result of the increasing distance between the Earth and the Moon? A. Total solar eclipses will occur only at Full Moon B. Total solar eclipses will last considerably longer C. Total solar eclipses will no longer occur D. Total solar eclipses will only be visible from the Earth s Southern Hemisphere E. Total solar eclipses will occur at every New Moon 27. Which physical law describing gravitational motion can explain the fact that comets spend most of their time far away from the Sun and little time close to the Sun? A. Newton s First Law B. Newton s Third Law C. The Universal Law of Gravitation D. Kepler s Second Law E. Kepler s Third Law 28. Which object has the most kinetic energy? A. a 3 kg mass moving at 3 m/s B. a 5 kg mass moving at 2 m/s C. a 1 kg mass moving at 5 m/s D. a 25 kg mass moving at 1 m/s E. a 100 kg mass which is stationary 29. Acceleration is: A. the rate of speed of the body in motion B. the variation of velocity of a body C. the effect of gravity D. the result of Newton s Third Law E. what prevents planets from falling into the Sun

6 30. Galileo s observations showed that: A. Jupiter has moons going around it like a mini-solar System B. the Milky Way consists of billions of planets too faint to be seen with naked eyes C. the Earth was the center of the Solar System D. Saturn showed distinct phases like the Moon E. telescopes were not yet good enough to be useful 31. What causes seasons on the planet Earth? A. The periodic changes in the heat retention of the Earth s atmosphere. B. The elliptical orbit of the Moon C. The tilt of the Earth s axis D. The alignment of the solar and lunar cycles E. The Earth s elliptical orbit, which brings it closer and farther from the Sun 32. What is the period of a comet if its average orbital radius is 4 AU? A. 1 year B. 2 years C. 4 years D. 8 years E. 16 years 33. A comet has an elliptical orbit, and at its closest approach its distance from the Sun it is about half than the distance at the point of largest separation from the Sun. If its speed is 10 km/s at its largest separation, what would be its speed at the closest separation? A. 2 km/s B. 5 km/s C. 10 km/s D. 20 km/s E. 40 km/s 34. If the Earth s axis were tipped 35 degrees instead of 23.5 degrees, seasons on Earth would be A. much less severe B. much more severe C. much longer D. much shorter E. hotter in the Northern Hemisphere, colder in the Southern

7 35. If the Earth had half its current mass, but same distance from the Sun, the gravitational pull of the Sun would be: A. 4 times the current pull B. twice the current pull C. the same as a current pull D. half the current pull E. ¼ the current pull 36. You are an astronaut returning to the Space Shuttle after fixing the International Space Station with a hammer. As you are jetting back to the shuttle, your lifeline breaks, your jets run out of fuel, your radio goes dead, and you miss the shuttle. To get back safely, you should: A. throw the hammer at the shuttle to get someone s attention B. throw the hammer away from the shuttle C. make a hammering motion in the direction of the shuttle D. make a hammering motion away from the shuttle E. use a swimming motion with your arms and legs. 37. The shuttle is now lifting off from its launch pad, after blasting propellant out of its thrusters. The force to lift the shuttle was provided by: A. the propellant releasing its chemical potential energy B. the propellant pushing against air molecules in the atmosphere C. the propellant pushing the shuttle up by heating and expanding the air beneath it D. the propellant accelerating down, giving a reaction thrust to the shuttle E. the propellant pushing the shuttle after hitting the ground and bouncing back 38. The difference between speed and velocity is: A. velocity is calculated using a physics equation B. velocity is the same as acceleration whereas speed is different C. velocity also includes a direction D. they are expressed in different units 39. In which of the following locations is the length of daylight 12 hours throughout the year? A. Only at the equator B. At latitudes closer than 23.5 degrees to the equator C. At latitudes greater than 47 degrees from the equator, north or south D. At latitudes between 23.5 and 47 degrees north or south E. Nowhere on Earth

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9 Solutions: 1. C 2. A 3. C 4. B 5. E 6. A 7. B 8. E 9. B 10. A 11. D 12. B 13. C 14. B 15. C 16. E 17. B 18. B 19. B 20. A 21. E 22. C 23. B 24. C 25. E 26. C 27. D 28. A 29. B 30. A 31. C 32. D 33. D 34. B 35. D 36. B 37. D 38. C 39. A