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33 Cards in this Set
- Front
- Back
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According to DR Kaku, what are the two greatest breakthroughs in physics...last 400 years
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Newton: laws of motion, gravity, calculus
Einstein: Energy= Mass times the square of the speed of light |
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what evidence is there that the earth is round ?
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ships over the horizon
shadows of the moon space photos of earth |
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Keplers first law says that a plants is not a circle
what shape why not exact |
ellipse
gravity from other plants pull us around a little |
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Newton's contributions to physics
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gravity theory
laws of motion calculus |
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difference between astronomy and astrology
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astronomy is the study celestial objects whereas astrology is a bunch of voodoo fortune telling horse ****
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difference between an element and a compound
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element can not be broken down into simpler substances and are primary constituents of matter
compound is two or more atoms |
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three stages of matter
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gas
liquid solid |
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structure of an atom and molecule
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nucleus with a protons and sometimes a neutrons
molecule is a substance comprised is two or more atoms bonded together |
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how does hydrogen differ from uranium
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hydrogen is the lightest element whereas uranium is the heaviest naturally element or close to it
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mean by temperature and pressure of a gas
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temperature is the motion of the gas
pressure is the force exerted on a container |
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what happens during combustion and photosynthesis
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combustion
carbon + oxygen equals carbon dioxide + energy photosynthesis carbon dioxide + water equals sugar + oxygen |
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what is your weight in newtons
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w=mg (weight = mass x gravity)
w=146 x 9.8 w= 1430.8 N mass must be in kg gravity is 9.8 m/s^2 |
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a car goes from 0 to 100km/hr in 10 sec
what is its acceleration in meters /sec^2? |
a=v/t (100/10) X (1000/3600) = 2,78 m/s^2
1000 = km to m 3600= sec in hr |
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if galileo dropped a 1 kg. ball off a tower how long before it hits the ground
how long for 5 kg ball? tower is 56 meters tall |
56=1/2(9.8)t^2 t equals the square root of 112 divide by 9.8 = 3.4 sec
times both sides by two to get rid of fraction same for 5 kg ball |
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it took scientists more than 200 years to find out that newtons laws were not exact. why ?
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they didn't have measurements at very large velocities (relativity)
and very small distances (quantum theory) |
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describe an experiment to measure g, the acceleration due to gravity at the earths surface
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measure velocity of tossed ball
slope of graph of velocity vs time is g (gravity) |
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in the experiment where you measured the motion of a ball in free fall, how did you determine that energy was conserved? what happened to the energy if the ball hits the floor.
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1/2mv^2 + mgh = constant
thermal energy |
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if a 100 watt light bulb is left on all day, how much energy does it use (in joules)? How much does it cost if the price of electricity is 20 cents per kilowatt-hour
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100 j/sec X 3600 X 24 = 8.64X 10^6 joules
kwh= (100X24)/1000= 2,4 times 20 cents = 48 cents |
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what are the first two laws of thermodynamics
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1) energy conserved
2)entropy increases energy moves from high temp to low temp |
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difference between F C K
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F = 9/5C + 32 F C K
32 0 273 K= C + 273 212 100 373 at 0K all motion stops |
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what types of waves have the longer than visible light?
which have the shorter wavelengths? |
Longer= IR/ microwave /tv /radar/ radio
shorter= uv / x ray / gamma |
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what is meant by the "big bang theory"
what is the evidence for it |
origin of the universe 13,5 bya
expansion from a very small singularity |
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what is dark matter and dark energy
how do we know they exist |
dark matter stabilizes galaxies
dark energy accelerates expansion |
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what is the difference between special and general theories of relativity
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special = constant velocity
general = acceleration |
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describe two experiments to test the special and general theories of relativity
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half life in an accelerator
"anomalous" precession of the perihelion of Mercury |
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the FM dial goes from 88 to 110 megahertz. what is the range of FM wavelengths
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^=c/f
lambda equals speed of light divided by the frequency in hertz max 3 x 10^8 / 88 x 10^6 = 3.4m min 3 x 10^8 / 110 x 10^6 = 2,7m |
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what is the current in amps which pass through a resistance of 100 ohms which is plugged into a 120 volt outlet?
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V=IR....V/R=I
I = 120V/100R = 1.2 amps |
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what is radioactivity
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disintegration of the nuclei
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difference between alpha and beta emitters
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alpha = helium nucleus
beta = electrons |
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difference between fission and fusion
besides the spelling |
nucleus splits apart in fission
nucleus fuse together in fusion |
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what is meant by fossil fuel
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coal oil natural gas
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advantage and disadvantage of nuclear power
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advantage = non-polluting
disadvantage = how to dispose the waste |
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what is meant by renewable energy
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hydroelectric=generators driven by water
biomass= corn fuel geothermal=steam from the molten core of the planet solar by wind of light energy |
