Astro 1 Final Exam 2025

Astro 1 Final Exam 2025 Which of the objects above is smallest in physical size? (regardless of the size of the picture) - -Planet with rings The Sun shines because it is - -Hot How often do total eclipses happen? - -rarely; once or twice a year, on average Where does fusion happen in a star? - -In the center Which chemical elements are involved in the main fusion reaction in our Sun? Choose TWO answers. - -Helium and Hydrogen How would you say this number in words? 600,000,000 - -six hundred million You live in State College. Let's say you go outside on April 1 and note the position of the Sun in the sky at noon -- when it reaches its highest point during the day. Then you go out again the following month (in May) and again note the position of the Sun in the sky at noon. In May, how will the Sun's noontime position compare to its noontime position in April? - -It will be higher in May If Earth's axis of rotation were NOT tilted, which of the following would be TRUE? - Pennsylvania would not get noticeable seasonal variation through the year; all the seasons would be about the same as one another If you are in the continental U.S., when does a vertical flagpole cast no shadow from your location? - -Never Which of the above diagrams best represents Earth's orbit around the Sun, as it would appear in a top-down view? - -Circle with sun in the middle what time is the waning gibbous moon high overhead? - -3am Choose the best match for each statement: revolve, rotate, or both. A) The sun does this: B) the Earth does this: C) This is a synonym for "orbit": D) This is a synonym for "spin" (On its own center axis): - -A) both B) both C) revolve D) rotate Astronomy Astronomy If Earth's orbit were changed to be a perfect circle (constant distance to the Sun), seasons would be... - -same as now. (hot summers, cold winters) How long does it take for the Moon to go through a full cycle of phases? - -one month During a solar eclipse, which object is lined up directly between the other two? - -moon Consider the following discussion between two students about the definition of light years: Student 1: I think I get light years. They are a unit of distance, like miles or kilometers. Student 2: I disagree. Just look at the word. It has "years" in it. It must be a unit of time, like seconds or days. But sure it can also be a unit of distance, because you sometimes hear that such-and-such astronomical objects is "five hundred light years away" for example. So it can be a unit of distance or time, depending on the situation. Which student(s) is/are correct, if either? - -only student 1 is correct Why do we see the Moon go through different phases? - -as the Moon moves around the Earth, an observer on Earth sees the Sun's rays on the Moon from different angles Imagine you are standing in the Northern hemisphere, like the observer in the figure above. Looking directly WEST, you see a star near the horizon. Which star at which position could it be? - -Star A at position 2 Consider the following discussion between two students about the cause of the phases of the Moon. Student 1: The phase of the Moon depends on how the Moon, Sun and Earth are aligned with one another. During some alignments only a small portion of the Moon's surface will receive light from the Sun, in which case we would see a crescent Moon. Student 2: I disagree. The Moon would always get the same amount of sunlight; it's just that in some alignments Earth casts a larger shadow on the Moon. That's why the Moon isn't always a full Moon.Which student(s) is/are correct, if either? - -neither; both are wrong My car's fuel tank holds fourteen (14) gallons of gasoline. If I used one-half (0.5) of a gallon of gasoline every day driving, how many days until my tank is empty? - -28 You drive 20 miles, and it takes you 30 minutes. What was your average speed in miles per hour (mph)? - -40 mph You observe a star rising due east. When this star reaches its highest position above the horizon, where will it be? - -high in the southern sky You build an accurate scale model of the Taj Mahal from legos. The real Taj Mahal in India is about 70 meters tall. Your scale model of it is 7 inches tall. Next you want to build a lego model of the Shanghai Tower, using the same scaling factor as before so you can accurately compare their relative heights. The real Astronomy Astronomy Shanghai tower in China is about 0.6 kilometers tall. How many inches tall should the Shanghai tower be in your lego model? - -60 inches Where on Earth would an observer have to be to see this view of the sky? - -middle latitude, between equator and pole If we took a time lapse photograph of stars, they would make streaks, or "star trails" on the photo along the dashed lines. What actually causes the stars to make these trails? - -the Earth slowly spins on its axis How long will it be before star A returns to its same position? - -24 hours Which direction are the star trails paths going as time proceeds? - -counterclockwise How long will it be before star D returns to its same position? - -24 hours Which star, if any, spends the LEAST number of hours above the horizon over the course of 24 hours? - -A Match each statement with whether it describes astronomy, astrology, or both. a) Which is the topic of this class? b) Which has to do with stars and constellations? c)Which is tantamount to fraud? d)Which is a field of science? - -a) Astronomy b) both c) Astrology d)Astronomy If the exchange rate between Euros and U.S. dollars is 1 Euro = 1.20 USD ($1.20), how much is 1.20 Euros worth in U.S. dollars? - -$1.44 Which phase would be high overhead at midnight? - -Full Which is a gibbous phase? - -4 (top left) Which position represents the new moon? - -1 (right) Which position corresponds to the moon phase pictured here? (Hint: it is one of the 'quarter' phases.) - -7 (bottom) During which phase could a lunar eclipse happen? - -5 (left) For an observer at these three different latitude regions on Earth, how much time is there between when a star rises and when it sets? Choose the best answer. a) equator b) pole Astronomy Astronomy c) middle latitude - -a) 12 hours b) stars never set c) it depends on the star Two students are having the following discussion regarding at what position(s) Star B rises and sets (if any), from the figure above: Student 1: The diagram shows that Star B is as low as it will get when it is just above the northern horizon at B3. So Star B never goes below the horizon. Student 2: Locations B2 and B4 are on my horizon because they are rising and setting just like A2 and A4. Which student(s) is/are correct, if either? - -only student 1 is correct If 100 countries each had 100 small cities, and each of those cities needed 10,000 doses of a vaccine, how many vaccine doses is that in all for all of those cities? - -100 million doses If you could type a 1,200 words in 2 hours, what would be your average typing rate in words per minute? - -10 Which statement below is NOT supported by the points shown on the graph above? - Sweden and Switzerland eat the most chocolate per person. Which of the following is not part of the electromagnetic spectrum? - -sound waves The greenhouse effect is ____ global warming. - -a necessary precursor for Pluto is a/an - -a Kuiper belt object. What color would the hottest stars appear to your eye? - -blue The Sun (a low-mass Main Sequence star) will eventually form which of the following? - -a white dwarf Which object has already lost its outer layers? - -D (bottom left) Which object will one day be (but is not yet) a red supergiant? - -A( top left) Which object is currently undergoing no nuclear fusion whatsoever? - -D (bottom left) Which main sequence star has the least mass? - -C (bottom right) Which object is a star most like our Sun is right now? - -B(middle on line) Which object has the smallest radius? - -D(bottom left) Astronomy Astronomy The figure above shows an HR diagram with points A-E that represent various stages in stellar evolution for the lives of stars. Note that only stars B, C, and D are main sequence stars. Put in order, from earliest to latest, the three stages in the life of a low mass star without a companion. Omit the stages shown on the diagram that do not apply. The first one is done for you. Earliest: D Next: B Latest? Two of the letters were not used. Why? - -E (top right) A(bottom left) those correspond to high mass stars, not low Refer to the spectra of two stars above. Which star is hotter: star A or star B? - -Star A (because it is closest to the left side i.e. the hotter spectra side) Imagine our solar system is moving in the Milky Way toward a group of three stars. Star X is a blue star that is slightly closer to us than the other three. Star Y is a red star that is farthest away from us. Star Z is a yellow star that is halfway between Stars X and Y. Which of these stars, if any, will give off light that appears to be redshifted? - -None of the three stars Consider the following discussion between two students about the different properties of light: Student 1: I think I get how light works. If you look at the chart of the electromagnetic spectrum, it shows that light with a higher frequency will also have a long wavelength. But it all has the same speed. Student 2: I disagree. If one type of light has a lot of energy and a high frequency it will have a faster speed than light that has a lower energy and a low frequency. Which student is right, if either? - -neither; both are wrong An X ray has a wavelength of 10-10 meters. What is its frequency? - -3x10^18 Hz Wavelength and energy are - -inversely proportional Consider the following student debate about what "weightlessness" means Student 1: The sensation of weightlessness occurs when an object is in freefall. That means that gravity is the only force acting on it. Since there is no surface for it to be resting on and pushing back up against gravity pulling down, the object couldn't feel its own weight. Student 2: Weightlessness occurs because there is very little gravity in space. Even though the gravity is technically not zero, above the Earth's atmosphere it is negligibly small. That's why astronauts in the space station cannot feel their weight. The higher they go, the less of their weight they would feel. Student 3: Weightlessness only occurs when there is no net force on an object at all. This is not actually possible in real life; everyone on or near Earth always has some net Astronomy Astronomy force on them at all times, even the astronauts. However the pressurized suits and shuttle - -Student 1 Consider the following debate between two students regarding the relationship between parallax angle and the distance we measure to a star. Student 1: The farther away a star is, the less it seems to shift due to parallax. That means the smaller we would measure for its parallax angle. So distance and parallax angle are inversely related. Student 2: If the distance to the star is more than 1 parsec, then the parallax angle must be more than 1 arcsecond. So a star that is many parsecs away will have a large parallax angle. Which student is right, if either? - -Student 1 Two stars, Omega and Zappa, have the same luminosity. Omega has a larger radius. Which star is hotter? - -Zappa is hotter (larger radius = hotter) Which of the following pieces of information is possible to ascertain from the spectrum of an object? its chemical composition whether it is moving toward or away all of the above/below what type of matter it is: dense and opaque, or diffuse gas its temperature - -all of the above/below What marks the end of a star's main sequence lifetime? - -it runs out of hydrogen in the core Star Beta has a parallax angle of 10 arcseconds. Therefore the distance to Star Beta is - -0.1 parsecs Consider these pictures of the three types of spectra, labeled A, B, and C: A (no lines, just rainbow) B (black with colorful lines) C (rainbow with black lines) Now consider these graphs of the three types of spectra, labeled 1, 2, and 3. These numbers do not necessarily match the numbers we gave these three types of spectra in our lecture notes. 1 (lines pointing upwards) 2 (lines pointing downwards) 3 (no line points) Match the picture (number) with the corresponding graph (letter) for each type of spectrum. Each option is used once. - -A) 3 B) 1 C) 2 Astronomy The grey blobs on the graph above encompass just where our solar system planets would appear on the graph. Each region includes at least two planets. Which region would include only Jupiter and Saturn? - -B Right blob with two sections. top section. A solid object has a temperature of 290K. At what wavelength does its thermal spectrum peak? 1 x 10 ? m. (What number goes in the exponent?) - --5 Which of the following determines the color of light? - -its frequency A parsec is larger than an Astronomical Unit. - -True Jupiter's average distance from the Sun is 5 AU, while Earth's average distance from the Sun is 1 AU. Moreover, Jupiter's mass is about 300 times larger than Earth. Therefore, compared to the Sun's gravitational force on the Earth, the Sun's gravitational force on Jupiter is - -12 times stronger can be visible in the sky for many weeks - -comet looks like a streak of light in a photograph of the sky - -both looks bright because of reflected sunlight - -comet only visible when passing through Earth's atmosphere - -meteor typically several AU away from the Earth when you see it - -comet [ Select ] ["high", "low"] Of low- or high-mass stars, identify which ones... are hotter? fuse H to He faster? live longer? fuse heavier elements during their life? go through a planetary nebula phase? - -high high low high low shaped like a flat ring-shaped disc - -both contains many small rocky bodies, each orbiting the Sun both - -both