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Physics - Power Watch

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    Hello,

    Could somebody please list all of the power equations that are needed for the Edexcel Physics course?
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    (Original post by JackMadeley)
    Hello,

    Could somebody please list all of the power equations that are needed for the Edexcel Physics course?
    I know the equation P=W/t, but what are the others?
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    Outside of that general definition of power, you only need to be aware of electrical power in particular, i.e P=IV and its substitutional derivates.
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    (Original post by sjgriffiths)
    Outside of that general definition of power, you only need to be aware of electrical power in particular, i.e P=IV and its substitutional derivates.
    So then I can use the equation V=IR and sub that in and those are all i need to know?
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    It may also be worth knowing P = I^2R

    This is derived from subbing V=IR into P=IV - sub IR in place of V.
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    (Original post by JackMadeley)
    So then I can use the equation V=IR and sub that in and those are all i need to know?
    Yep, to get P = I^2 * R = V^2 / R and, of course, also just applying P=E/t in the context of electrical energy rather than mechanical work (although technically it comes back to the same thing with regards to electric fields - what level is this at, out of curiosity?)
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    (Original post by JackMadeley)
    I know the equation P=W/t, but what are the others?
    You can derive another equation from that:
    You already know that W (work done) = Force(F) x Distance(d)
    Substitute that in and you get:
    P = (Fd)/t
    which is the same as
    P = Fx(d/t)
    speed = distance/time
    therefore:
    P=Force x Speed
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    (Original post by sjgriffiths)
    Yep, to get P = I^2 * R = V^2 / R and, of course, also just applying P=E/t in the context of electrical energy rather than mechanical work (although technically it comes back to the same thing with regards to electric fields - what level is this at, out of curiosity?)
    AS and A2, I was just looking for the equations for the entire subject.
 
 
 
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