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Homework Help: Order of magnitude problem

  1. Jan 22, 2006 #1
    Ok heres the question and what I have solved so far

    Grass grows densely everywhere on a 1/4 acre plot of land. What is the order of magnitude of the number of blades of grass? Explain your reasoning. Note that 1 acre = 43560 ft^2.

    Ok. 43560/4 to get the 1/4 acre = 10890 ft^2

    Now I have no experiance with order of magnitude problems yet, as I just started physics but I would guess to head in this direction.

    Figure there is an estimated 1 blade of grass per cm. Convert the ft to cm and get 30.48cm in a foot so there would be 331927.20 cm in 10890 ft meaning there is 331927.20 blades of grass in the 1/4 acre if this information was accurate, so what is the +/- factor of this or the order of magnitude rather..

  2. jcsd
  3. Jan 22, 2006 #2


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    Homework Helper

    Your basic calculation is in error. If there are 30.48 cm in 1 foot then there are (30.48)^2 cm^2 in 1 ft^2.
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