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    http://pmt.physicsandmathstutor.com/...%20A-level.pdf

    Question 4 (b) ii (and 4 b i, I'm confused as to why the electrostatic force acts left?)

    And part b ii I just dont really understand how to approach..

    Any help would be appreciated guys!

    Cheers
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    (Original post by iMacJack)
    http://pmt.physicsandmathstutor.com/...%20A-level.pdf

    Question 4 (b) ii (and 4 b i, I'm confused as to why the electrostatic force acts left?)

    And part b ii I just dont really understand how to approach..

    Any help would be appreciated guys!

    Cheers
    You know it's in equilibrium. Tension acts along the string, whose horizontal component would want to displace the bob right, gravity wants to make it go to the right so the electric force must go to the left, otherwise how else would it be in equilibrium?

    Then you just need to resolve along the direction perpendicular to the wire, using the force from the previous part and N2L - just in the way that you would approach a standard equilibrium question in M1.
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    (Original post by kingaaran)
    You know it's in equilibrium. Tension acts along the string, whose horizontal component would want to displace the bob right, gravity wants to make it go to the right so the electric force must go to the left, otherwise how else would it be in equilibrium?

    Then you just need to resolve along the direction perpendicular to the wire, using the force from the previous part and N2L - just in the way that you would approach a standard equilibrium question in M1.
    Ahhh cheers that makes a lot more sense, I got like 15.4 degrees, the answer says around 15.2 but I assume 15.4 would be marked correct?

    Thanks again
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    (Original post by iMacJack)
    Ahhh cheers that makes a lot more sense, I got like 15.4 degrees, the answer says around 15.2 but I assume 15.4 would be marked correct?

    Thanks again
    Are you rounding up your results before your final answer?
 
 
 
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