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Homework Help: Human tissue attraction

  1. Jun 26, 2008 #1
    Human tissue contains about 3*10^27 electrons per kg of material. Suppose two humans are located 1370 km apart and each has a mass of 60 kg. We now transfer 5*10^21 electrons from one person to the other. What will be the magnitude of the resulting attraction, rounded to the nearest newton?

    I used the equation F=kQ1Q2/r^2

    except I am not sure if I used the right charges.
    for Q1, i found it by ((3*10^27)(6)-(5*10^21))(1.6*10^-19)
    and Q2: ((3*10^27)(6)+(5*10^21))(1.6*10^-19)
  2. jcsd
  3. Jun 26, 2008 #2

    Andrew Mason

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    Why are you using 3 x 10^27? Those electrons are balanced by an equal number of protons so there is 0 net charge. You want to find the net charge after the transfer of 5 x 10^21 electrons.

  4. Jun 26, 2008 #3
    oh okay, thanks! the answer i got now is more reasonable =)
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