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    Working with electrostatic force - unknown charge problem

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    A positive charge of 2X10-12 Coulombs placed 10cm from another charge experiences a repulsive force of 9X10-9 Newtons. What is the sign and magnitude of the other charge?

    © BrainMass Inc. brainmass.com December 24, 2021, 4:47 pm ad1c9bdddf
    https://brainmass.com/physics/work/working-electrostatic-force-unknown-charge-problem-7721

    SOLUTION This solution is FREE courtesy of BrainMass!

    Since the charge experiences a repulsive force, the sign of the other charge is positive.
    (same charges repells)

    we have, F = AQ1q2/R^2 .....(1)

    where A = 9x10^9

    F = 9x10-9 N
    Q1= 2x10-12 C
    R = 10 cm = 10x10^-2m = 0.1m

    R^2 = 0.01 m

    from equation1 we get, q2 = F x R^2/A Q1

    Substitute the values of the parameters,

    q2 = [9x10-9 x0.01]/2x10-12 x 9 x 10^9

    = (1/2) x 10^-11 x 10^12 x 10^-9

    = 0.5 x 10^-8 Coulomb

    The answer to the last posting is as follows sorry for the mistake

    The charge of a proton is e= 1.6 x10^-19 coulomb

    The force between two charges F = AQ1q2/R^2

    where A = 9x10^9

    Here we have for this equation,

    1*10^-17 = 9x10^9 x 1.6 x10^-19 * 1.6 x10^-19 /R^2

    therefore, R^2

    = [9x10^9 x 1.6 x10^-19 * 1.6 x10^-19]/1*10^-17

    =2.56 x 9 x 10^9 x 10^-21

    Or the distance R = sqrt(25.6x10^-30) m

    =4.8x10^-15 m

    Answer

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    © BrainMass Inc. brainmass.com December 24, 2021, 4:47 pm ad1c9bdddf>
    https://brainmass.com/physics/work/working-electrostatic-force-unknown-charge-problem-7721

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