Term
| Which systems are bound together by gravity? |
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Definition
| The Earth, the Sun, the Galaxy and the local group of Galaxies |
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Term
| Approximately how many times the distance to the Galaxy's center is greater than the distance between the Earth and the Sun? |
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Definition
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Term
| How is a light year defined? |
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Definition
| the distance light travels in a year |
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Term
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Definition
| An average distance between the Earth and the Sun |
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Term
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Definition
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Term
| Approximately how many times the period of the Sun'd rotation about the galaxy's center is greater than 1 year? |
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Definition
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Term
| Smallest to largest particles |
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Definition
| quark, proton, atom, molecule |
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Term
| Smallest to largest systems |
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Definition
| Planet, star, galaxy, local group, galaxy cluster |
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Term
| How many times the mass of the Universe at a critical density is greater than the mass of the galaxy? |
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Definition
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Term
| About how much larger is the Sun than Earth? |
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Definition
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Term
| The Second Newton's law specifies the relationship |
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Definition
| Between a force excerted on a body and acquired acceleration as a result |
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Term
| Kinetic energy of a moving body is |
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Definition
| proportional to the body's mass, proportional to the square of the body's velocity and is always non-negative |
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Term
| A planet's motion is completely characterized by |
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Definition
| It's distance from the central star (or coordinates) and an orbital velocity along its orbit |
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Term
| As distance between two stars becoems twice smaller, the force of gravity exerted on them |
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Definition
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Term
| When a spinning skater pulls in her arms to turn faster |
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Definition
| her angular momentum remains the same |
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Term
| The gravitational tidal force created by the moon |
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Definition
| slows down Earth's rotation rate and stretches Earth along the Earth-Moon line, causing tidal bulges |
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Term
| Conservation of angular momentum suggestes that |
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Definition
| as a body contracts, it starts to spin faster and as a body expands, it starts to spin slower |
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Term
| Gravitational potential energy of a planet orbiting its central star is |
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Definition
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Term
| The First Newton law specifies that |
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Definition
| A body will move with constant speed along a straight line if there is no net force applied to it |
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Term
| Law of Universal Gravitation can be applied to |
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Definition
| planetary motions around their central star, stellar motions around the center of our Galaxy, motion of the Milky Way Galazt in a cluster of galaxies, motions of spacecraft around the Earth and motion of the Moon around the Earth |
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Term
| Newton's Third Law is obseved when |
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Definition
| two bodies interact with each other |
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Term
| To "break free: from the Earth's gravitational field, a body needs |
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Definition
| to circle around the planet |
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Term
| A body's weignt on a planet depends on |
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Definition
| the planet's mass, radius, and gravitational acceleration |
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Term
| An astronaut on the International Space Station (ISS) experiences weightlessness |
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Definition
| because the astronaut and the ISS both experience free fall due to the Earth's gravity force |
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Term
| If observations show that a celestial body moves along a curved line then we conclude that |
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Definition
| its motion is affected by an external force such as gravity, another massive body exerting gravitational force on it, it is experiencing centripetal acceleration and its velocity changes along the body's trajectory |
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Term
| Conservation of linear momentum suggests that |
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Definition
| the total linear momentum before collision of two pool balls equals to their total momentum after the collision |
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Term
| The law of conservation of energy suggests that the total amount of energy in the Universe |
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Definition
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Term
| When the Earth, Moon, and Sun are aligned with respect to each other, then we should always observe |
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Definition
| the highest tides called Spring Tides |
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Term
| Escape velocity from a planet depends on |
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Definition
| the planet's mass to radius ratio |
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Term
| The Moon spirals away from us at a rate of about 2 inches per year because of |
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Definition
| the gravitational tidal force exerted by Earth to the Moon |
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Term
| As light from an opaque object (star) passes through a prisim it produces |
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Definition
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Term
| Refraction of light waves occurs |
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Definition
| when a wave changes direction of propagation as it passes from one medium to another at any angle other than 90 or 0 degrees |
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Term
| As light from a star passes through a rarefield cold gas and then passes through a prism, it produces |
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Definition
| an absorbtion line spectrum |
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Term
| The wavelength of a light wave is |
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Definition
| the distance between two successive crests or two successive valleys |
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Term
| The frequency of a light source at 100 MGh (Megahertz) corresponds to the wavelength of |
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Definition
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Term
| Which spectral bands are blocked by the Earth's atmosphere? |
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Definition
| X-ray, Gamma Ray, Most of the IR band and long wavelength radio emission |
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Term
| Absolute zero temperature corresponds to |
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Definition
| the minimum possible kinetic energy of thermal motions of atoms and molecules in a body |
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Term
| A photon's energy is proportional to its |
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Definition
|
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Term
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Definition
| an electromagnetic wave and an oscillation of electric and magnetic fields in two mutually perpendicular planes to the direction of light propagation |
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Term
| The wavelength of a light wave gets shorter |
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Definition
| when its frequency get higher |
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Term
| What type of waves exhibit the Doppler effect? |
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Definition
| Sound waves, gamma rays, x rays and water waves |
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Term
| As a light source moves away from an obseved, the wavelength of the observed emission lines |
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Definition
| becomes loner (or red-shifted) |
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Term
| As a star becomes twice hotter, its emitting power |
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Definition
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Term
| As a body gets hotter, it emits most of its energy in |
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Definition
| a shorter wavelength and in a radio band |
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Term
| An atom will be excited from its ground state to a higher state if |
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Definition
| it absorbs a photon with the fixed energy corresponding to the energy difference between states |
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Term
| Waves manifest themselves as |
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Definition
| longtitudinal or transverse, as periodic disturbances propagating energy in space and time and distrubances with a characteristic wavelength and frequency |
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Term
| As light from a rarefied hot gas passes through a prisim it produces |
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Definition
| an emission line spectrum |
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Term
| As a star moves toward an observer, the wavelength of the observed absorption lines |
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Definition
| becomes shorter (or blue-shifted) |
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Term
| Which spectral band has the longest wavelength? |
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Definition
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Term
| The highest energy photons belong to the |
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Definition
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Term
| The resolving power of a telescope with a large mirror is |
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Definition
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Term
| To construct an image gamma-ray telescope, use |
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Definition
| particle properties of light |
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Term
| An amateur telescope with the focal lenth of an objective, F=1000 mm and the focal length of an eyepiece, f=10 mm, will produce a magnification of |
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Definition
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Term
| Radio telescopes need to have larger apertures to |
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Definition
| increase their light gathering power to collect weak radio signals and to increase their resolving power to observe fine structures of radio sources |
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Term
| Refractors have disadvantages over reflectors because |
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Definition
| their primary objective (lens) suffer from chromatic aberration, ther primary objective (lens) under their own weight, their greater manufacturing cost and two sides of the refractorr telescope's objective need to be perfect rather than one side in reflectors |
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Term
| X-ray telescopes cannot be used for observations from the Earth's surface because |
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Definition
| X-ray emission is blocked by the Earth's atmosphere |
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Term
| Adaptive optics can increase the angular resolution of an image by |
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Definition
| correcting for the effects of atmospheric turbulence in real time |
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Term
| The Keck's telescope mirror is about 4 times larger in diameter than the Hubble Space Telescope's (HST) mirror. How much greater is Keck's light gathering power with respect to the HST's? |
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Definition
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Term
| A telescope's resolving power measures its ability to view |
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Definition
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Term
| A ground-based IR telescope would |
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Definition
| be worthless because most of IR emission can not pass through the Earth's atmosphere |
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