i>clicker Questions A scientific law is something that has been proven to be true. A. True B. False C. Only in experimental sciences.

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1 A scientific law is something that has been proven to be true. A. True B. False C. Only in experimental sciences. i>clicker Questions The fifth planet from the sun, the sixth planet and the seventh planet (in order) are: A. Saturn, Uranus, Neptune. B. Mars, Jupiter, Saturn. C. Jupiter, Saturn, Uranus. D. Saturn, Jupiter, Uranus. Astronomers measure the distance from the earth to Mercury by. A. Measuring the length of time it takes for sound to reach us from Mercury. B. Measuring the length of time it takes for light to reach us from Mercury. C. Measuring the different apparent position of Mercury relative to the stars for two observers on earth separated by an appreciable distance. D. Using a very long ruler. According to Kepler s Laws: A. Planets rotate around the sun in circular orbits. B. A planet s orbital speed is faster as it gets farther from the sun. C. The time it takes Neptune to complete an orbit of the sun is longer than the time it takes the earth to complete its orbit. D. The earth s orbit is more nearly circular than Venus orbit. E. The sun orbits the earth in an elliptical orbit. If the sun and all of its mass were to suddenly disappear, the Earth would, A. Fly off into space on a straight line. B. Continue unchanged in its current orbit. C. Continue in its orbit but with a different orbital speed. D. Stop spinning.

2 The orbit of Io, one of Jupiter s moons, is governed by: A. Kepler s Third Law. B. Newton s First Law. C. Galileo s telescopic principle. D. Newton s Universal Law of Gravity. E. Copernicus Law of Orbital Precession. Electromagnetic radiation consists of the following: A. Vibrating molecules. A. Longitudinal waves. B. Oscillating electrons. C. Electric and magnetic fields that oscillate in the direction of wave propagation. D. Oscillating electric and magnetic fields that are perpendicular to each other and to the direction of wave propagation. How do the spectral lines of a galaxy moving rapidly towards us appear? A. Brighter. B. Dimmer. C. Red-shifted. D. Blue-shifted. E. Broadened. Basically, how did the planets form? A. They were ejected from the Sun following a close encounter with another star. B. They were formed from the same flattened swirling gas cloud that formed the Sun. C. They evolved from an ancient galaxy. D. They were captured by the Sun as they drifted through space. E. They were formed from material ejected by the Sun. If the Earth had no Moon, then the tides A. Would not occur. B. Occur more often and with more strength. C. Still occur but be barely noticeable. D. Occur with the same frequency but be less strong. E. Occur only once a day instead of twice.

3 The major constituents of the Earth s atmosphere are: A. 95% carbon dioxide and some water vapor. B. 77% nitrogen, 21% oxygen. C. 77% oxygen, 21% nitrogen. D. Methane, carbon dioxide, and water vapor. E. Hydrogen, helium and oxygen in roughly equal amounts. A greenhouse exposed to sunlight gets warm because: A. The visible light can penetrate the glazing but the re-radiated infrared cannot. B. The glazing insulates the interior from the cooler outside air. C. The glazing traps visible light inside the greenhouse. D. The glazing prevents ultraviolet rays from escaping. E. Carbon dioxide inside the greenhouse is trapped inside. The third brightest object in the sky is: A. The Moon. B. The Andromeda nebula. C. Orion s belt. D. Venus. E. Mars. How does the Sun produce the energy to radiate so brightly? A. Gravitational collapse. B. Combustion of hydrogen. C. Nuclear fission. D. Nuclear fusion. E. Energy left over from its formation. What fundamental force is responsible for holding the nucleus together? A. Gravity. B. Electromagnetic force. C. Strong nuclear force. D. Weak nuclear force. E. Magnetic force. The most tightly bound nucleus is: A. H 1 (hydrogen).

4 B. H 2 (deuterium). C. He 4 (helium). D. Fe 56 (iron). E. U 238 (uranium). The Sun is the closest star to the Earth. Approximately how close is the next nearest star? A. 93,000,000 miles. B. 500 light-seconds. C. 1 light-year. D. 4 light-years. E. 100 light years. How is the temperature of the surface of a star is measured? A. By measuring the frequency of the peak of the light spectrum. B. By measuring the intensity of the emitted light. C. Using the apparent magnitude and measured distance to the star. D. By measuring the absorption spectrum. E. By measuring the red shift. Consider two stars with the same surface temperature. If Star A is larger than Star B, then which of the following must be true? A. Star A appears brighter than Star B. B. Star B has a higher apparent magnitude than Star B. C. Star A is closer than Star B. D. Star B is redder than Star A. E. Star A has a larger luminosity than Star B. If two stars are the same size, which of the following must be true? A. The cooler star appears to be bluer. B. The cooler star appears to be redder. C. The closer star appears to be brighter. D. The cooler star appears to be dimmer. E. The closer star appears to be bluer. What is the most fundamental star property that determines where it is found on the main sequence? A. Radius. B. Luminosity.

5 C. Temperature. D. Mass. E. Distance from Earth. Why do stars tend to form in groups? A. It s just a statistical fluctuation. B. A large interstellar cloud fragments into smaller clouds that eventually form stars. C. Star clusters form after star formation is complete and stars start to swirl around each other. D. When stars are forming, they gravitationally attract each other. E. This is false stars do not tend to form in groups. Nuclear fusion in the Sun will: A. Never create elements heavier than helium. B. Create elements up to and including oxygen. C. Create elements up to and including iron. D. Create elements up to and including uranium. E. Cause heavy atoms to split into lighter atoms. An isolated white dwarf produces energy by: A. Nuclear fusion. B. Nuclear fission. C. Gravitational collapse. D. Radiation pressure. E. A white dwarf does not produce energy. How do we know there is dark matter in the Milky Way Galaxy? A. We observe it. B. We detect it by observing their spectra. C. By studying the rotation curve. D. By weighing the Galaxy. E. By seeing dark places in the Galaxy.

6 Why do we believe there is a massive black hole at the center of our Galaxy? A. We see it with the Hubble Space Telescope. B. By measuring orbits of stars near the Galactic center. C. By understanding the orbit of the Sun. D. From infrared observations. E. From watching matter fall into it. In which part of the galaxy is the Sun located? A. Galactic center. B. Galactic bulge. C. Galactic halo. D. Galactic disk E. Galactic black hole. Stars in the spiral arms of the Milky Way galaxy: A. Are stationary. B. Have orbits around the Galactic center that are mostly out of the plane of the disk. C. All have the same orbital period around the Galactic center. D. Orbit the Galactic center following Kepler s Laws. E. Have random orbits. Vesto Sipher found that the spectra from most galaxies are red-shifted. This means that: A. Most galaxies contain old stars. B. Most galaxies contain new stars. C. Most galaxies contain dust. D. Most galaxies are moving towards us. E. Most galaxies are moving away from us. What is the source of the huge energy that an active galaxy produces? A. Nuclear fusion. B. Slowing of the spin of a supermassive black hole. C. Spinning magnetic fields. D. Supernovae. E. Matter falling into a supermassive black hole.

7 Which of the following is true about dark matter? A. There is only evidence for dark matter in the Milky Way Galaxy. B. Most dark matter is in the form of brown dwarfs. C. About 90% of all matter in the universe is dark matter. D. About 50% of all matter in the universe is dark matter. E. Dark matter does not exert a gravitational force on non-dark matter. Collisions between galaxies can: A. Turn irregular galaxies into elliptical galaxies. B. Cause both galaxies to collapse into a supermassive black hole. C. Cause bursts of star formation in starburst galaxies. D. Cause large numbers of stars to collide and explode. E. Hardly ever occur as galaxies are so far apart. We appear to be at the center of the Hubble flow (i. e. all distant galaxies moving away from us). Why doesn t this violate the cosmological principle? A. Every other place in the universe appears to be at the center also. B. It does violate the cosmological principle but only at one place. C. The cosmological principle was only a theory. D. The expansion looks the same in all directions. E. This is just a local fluctuation. What fraction of the matter density of the Universe is made of atoms? A. 100% B. 50% C. 20% D. 3% E. Less than 1%

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