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    i been given a diagram of a field. using it i can determine the voltage at a point and the distance between two charges. from this i can deduce the force. i then get asked to work out the magnitude and direction of an electron experiencing the force at this point. my minds gone to pot, how do i do it?
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    (Original post by El Chueco)
    i been given a diagram of a field. using it i can determine the voltage at a point and the distance between two charges. from this i can deduce the force. i then get asked to work out the magnitude and direction of an electron experiencing the force at this point. my minds gone to pot, how do i do it?
    You can work out the voltage using the formula E = V/d (V = Ed)
    You can work out the force on the electron using E = F/Q
    Hope this is of some use
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    (Original post by josklkr)
    You can work out the voltage using the formula E = V/d (V = Ed)
    You can work out the force on the electron using E = F/Q
    Hope this is of some use
    FEQ! :rolleyes: i knew there was a reason thse questions made me swear... thanks dude.
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    (Original post by El Chueco)
    FEQ! :rolleyes: i knew there was a reason thse questions made me swear... thanks dude.
    Please i could help
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    (Original post by josklkr)
    You can work out the voltage using the formula E = V/d (V = Ed)
    You can work out the force on the electron using E = F/Q
    Hope this is of some use
    Im not sure you can do that. That formula is for capacitors where you assume a uniform field - that isnt the case here. Maybe you can get away with it at A level but Id do it like this:

    V = Q/4piEor ---> rearrange to find Q

    bang Q into:

    F = Q1Q2/4piEor^2

    Edit: just to clarify do we have 2 charges and then an electron or is an electron 1 of the 2 charges. My method works if its 1 of the 2 charges otherwise you would need a superposition
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    (Original post by El Chueco)
    i been given a diagram of a field. using it i can determine the voltage at a point and the distance between two charges. from this i can deduce the force. i then get asked to work out the magnitude and direction of an electron experiencing the force at this point. my minds gone to pot, how do i do it?
    if they are point charges use the eqtns:

    F= Q1xQ2 / r^2 (if you know the two charges)

    and E=F/Q1 (if you know the fieldstrengh and one charge)

    Don't think you can use E=V/d, unless its a uniform field

    pk

    P.S. "FEQ" - what a lame joke :rolleyes:
 
 
 
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