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Homework Help: Emergency hw help

  1. Jun 7, 2010 #1
    1. The problem statement, all variables and given/known data
    When sugar is poured from the box into the sugar bowl, the rubbing of sugar creates a static electric charge that repels the grains. If each of two sugar grains acquires a charge of 3.0x10(to the negative 11th power) at a seperation of 8.0x10(to the negative 5th power)


    2. Relevant equations
    electrostatic force= (electrostatic constant)(charge 1)(charge 2)/(distance)(2nd power)



    AND



    1. The problem statement, all variables and given/known data
    Each of two hot-air balloons acquires a charge of 3.0x10(to the negative 5th)C on its surface as it travels through the air. How far apart are the balloons if the electrostatic force between them is 8.1x10(to the negative 2nd)N?


    I have no idea how to do this :( plz help
     
  2. jcsd
  3. Jun 7, 2010 #2
    Re: Emergency hw help SAVE MY GRADE :(

    ahhhhhh :(
     
  4. Jun 7, 2010 #3
    Look carefully at Coulomb's law:

    [tex]\left|\vec{F}_{elec}\right|=\frac{1}{4 \pi \epsilon_{0}}\frac{q_{1}q_{2}}{r^{2}}[/tex]

    Just identify the given quantities with the variables in each problem and do some algebra to solve for the unknown.
     
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