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Homework Help: Er i don't get it? Help lol

  1. Sep 19, 2004 #1
    ok so far i have

    light from the sunr eaches Earth in 8.3 min.
    The velocity of light is 3.00 x 10 to the eighth power m/s . How far is earth from the sun

    so far i have the formula Delta d ( avg distance) = v (velocity) x delta t(avg speed)

    so far i converted 8.3 minutes = 8.3 x 60 = 498= 500 < -- do i use sig figs?

    and my final equation became delta d = (3.00x10 to the eight power) x 500 = 1.5 x 10 to the eleventh power.. somehow i don't think its right.. cuz i looked at the answer key and it said 2.5 m/s please help me get the right steps
  2. jcsd
  3. Sep 19, 2004 #2


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    The speed of light is [itex]3 \times 10^8[/itex] METERS per second.
  4. Sep 20, 2004 #3
    yes and well? sorry lol
  5. Sep 20, 2004 #4

    Math Is Hard

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    why would the answer be in meters per second if you are trying to find distance? that doesn't make sense.
  6. Sep 20, 2004 #5


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    You're introducing round off errors way too soon. Only round the very final answer.

    I get the same answer as you though.
  7. Sep 20, 2004 #6
    Maybe the answer is written down wrong, the closer the figures to c, and when not rounding 498, you get even less than 1.5. About, 1.443 or so
  8. Sep 20, 2004 #7


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    Are you sure you looked at the right question in the answer key? Your answer is correct. The question asks for distance and 2.5 m/s is a measure of velocity, so the answer key can't be correct.
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