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88 Cards in this Set
- Front
- Back
What causes day and night?
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Rotation of the Earth on its axis
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How does the Sun appear to move in the sky in the course of a day?
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east to west because of the earth's rotation
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what time of day does the sun transit the meridian?
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noon
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what happens to the earth in one year?
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it orbits the sun one time
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why do we have seasons?
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tilt of the earth's axis (not changing distance from Sun)
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how is the earth's axis tilted when we have summer in the northern hemisphere?
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with the north pole towards the sun
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what season is it in the southern hemisphere when it is winter in the northern hemisphere?
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winter
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When does winter begin?
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Dec 21st nights longer than days |
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When does spring begin?
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March 21st days and nights equal length |
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when does summer begin?
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june 21st days longer than night |
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when does fall begin?
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sept 21st days and nights equal length |
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would seasons still happen if the earth axis was not titled?
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no seasons would happen
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what happens to the moon in 1 month?
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it moves around the earth once
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what causes the phases of the moon?
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sun is lighting different fractions of the part of the moon that we see.
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what is the order of the phases of the moon?
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new-first quarter-full-third quarter-new
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when is the full moon visible?
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only at night
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when is the new moon visible?
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the new moon is visible during the day and sets at sunset
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how are the sun, earth, and moon positioned when it is new moon?
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sun-moon-earth
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What is a solar eclipse?
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moon blocking the sun's light
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how are the sun. earth, and moon positioned when it is full moon?
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sun-earth-moon
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what is a solar eclipse?
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moon blocking the sun's light
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how are the sun, earth, and moon positioned when it is a solar eclipse?
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sun-moon-earth
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what is a lunar eclipse?
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earth's shadow on the moon
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how are the sun, earth, and moon positioned when it is a lunar eclipse and what phase is the moon in?
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sun earth moon;full
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why don't eclipses occur every month on earth?
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the moon orbits the earth in a different plane than the earth orbits the sun
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what is a constellation?
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big areas of the sky; everything in that region is part of that constellation
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how many constellations are there?
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88
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Are stars in the same constellation all the same distance from us?
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no not at all they are all at different distances
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are all constellations visible at the same times of year?
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no they are all different. |
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what is ecliptic?
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location of the sun with respect to the stars
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Where are zodiac constellations?
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they are along the orbit of the earth around the sun
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is the sun in a zodiac constellation ?
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in each for a month each year |
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can you see the zodiac constellation if the sun is in it?
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nope bc behind sun and nighttime side faces away
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During the month you were born the sun was...
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in the constellation of your zodiac
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what are winter zodiac constellations?
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ones opposite the sun in the winter
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what are summer zodiac constellations?
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ones opposite the sun in the summer
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Which constellations are we responsible for recognizing?
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orion the hunter, Cygnus the swan, ursa major the great bear, Scorpius the scorpion
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orion the hunter steps:
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Cygnus the swan steps:
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ursa major in the great bear steps:
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Scorpius the scorpion steps:
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what is the summer triangle?
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three prominent stars visible in the summertime sky
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What are the properties of light?
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light has some properties of a wave and other properties of a particle.
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what is a particle of light called?
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photon
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List from high energy to low energy.
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gamma rays- x-rays-uv-optical-ir-radio
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radiation parts?
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energy high-frequency high-wavelength low
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What are the wave lengths of radio waves measured in?
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meters and centimeters
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What are the wavelengths of visible light?
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angstroms
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What are angstroms?
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ten billionths of a meter
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What are the wave lengths of x rays?
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even smaller
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How does the prism split into different colors?
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by bending different wavelengths by different angles
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What is the blackbody spectrum?
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With higher temperature there is more light which peak to shorter wave length
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what kinds of radiation get through the earth's atmosphere?
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optical and radio
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What is the continuous spectrum?
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light at all wavelengths (kirchoff's laws)
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what are absorption lines?
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dark lines in the spectrum at certain wavelengths( kirchoff's law)
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How are absorption lines produced?(kirchoff's law) |
they are produced by gas cloud blocking light source; atom absorbs photon and electron moves from lower to higher level
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What are emission lines?
(kirchoff's law) |
bright lines at specific wavelengths(kirchoff'slaw)
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How are emission lines produced? (kirchoff's law) |
they are produced by hot gas; atom emits photon and electron moves higher to lower level
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how are different chemical elements distinguishable?(kirchoff's law)
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they have different energy levels that their electrons can occupy and thus give rise to different spectra
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what is redshift?(kirchoff's law)
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redshift as a source moves away the wavelength and gets longer
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What happens to the lines when the redshift occurs?(kirchoff's law)
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lines shifts to the red and frequency decreases
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What is a blue shift?(kirchoff's law)
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as source approaches the wavelength gets shorter
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what happens to lines of a spectrum in a blue shift?m(kirchoff's law)
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liens in the spectrum shift to the blue and frequency increases
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what is the Doppler effect?(kirchoff's law)
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it is an analogous effect for sound
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What do reflecting telescopes have?
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mirrors
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What do refracting telescopes have?
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lens
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What are important qualities of telescopes?
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light gathering power, angular resolution, and the quality of the instruments
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What Is not so important about telescopes?
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magnification
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Where do telescopes collect light?
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in proportion to the area of their mirrors
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What is the area of a circle proportional to?
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the diameter squared ex. a 2 meter telescope collects 4 times as much light than a 1 meter telescope |
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What is angular resolution?
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it can separate two nearby light sources
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How does angular resolution separate two nearby light sources?
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with good angular resolution
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What atmosphere limits angular resolution?
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earth's atmosphere, thus stars twinkle
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What happens when we magnify?
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we see more detail but also observe a smaller area of the sky.
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Why are telescopes above the earth's atmosphere better?
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1. certain kinds of radiation cannot get through atmosphere (x-ray gamma-ray, uv, ir) 2.give clearer images without atmospheric blurring |
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Why are telescopes above earth worse?
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because it is hard to get a very large collecting area launched into space
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who's model was the geocentric system and what did it show?
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It is an ancient greek model of an earth centered solar system
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What is the heliocentric model?
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it is the modern correct sun centered system
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how do planets move in a retrograde loop?
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planets move eastward from night to night, then slow down and move westward from night to night and then back to eastward
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Why does the retrograde loop happen for planets?
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This happens for planets that orbit the sun slower the earth does so that the earth overtakes them their orbits they appear to move backards
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what is newton's first law?
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an object at rest or in motion in a straight line at a constant speed will remain in the state unless acted upon by a force ex. if sun disappeared earth would still continue in its usual direction |
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What is newton's second law? what is the equation? What moves faster?
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the acceleration of a body due to a force will be in the same direction as the force, with a magnitude directly proportional to its mass Force=mass x acceleration thus smaller mass will move faster if force is applied to it |
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what is newton's third law?
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for every action, there is an equal an opposite reactions ex. the sun exerts force on planets and they orbit it. The planets exert force on the sun but because the sun is so larger it only ,moves relatively little |
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What is newton's law of universal gravitation?
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force of gravity proportional to mass of object 1 x mass of object 2 divided by the distance between two objects squared
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what does more mass mean? |
more gravity
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what does larger separation mean?
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less gravity
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what is 2 times further away?
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1/(2 squared) = 1/ (2x2)= 1/4th as much gravity
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