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    This question is driving me mad :woo:
    I was revising for other exams and since I didn't have a mechanics exam everythings gone out the window :mad:

    This question has totally stumped me, I drew a diagram but I don't even know if that's right. Anyway here's the full question:

    Two forces, (4i - 5j)N and (pi + qj)N, act on a particle P of mass mkg. The resultant of the two forces is R. Given that R acts in a direction which is parallel to the vector (i - 2j),

    (a) find the angle between R and the vector j

    (b) show that 2p + q + 3 = 0

    Given that also q = 1 and that P moves with an acceleration of magnitude 8(square root)5 m s^-2 ,

    (c) find the value of m

    Any help is appreciated
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    Help please :/
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    Oh well
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    a) find the angle between (i - 2j) and vector j. Vector R is parallel to (i -2j) which means it's simply a multiple of that vector.

    b) dunno yet.

    c) solve the equation to get p, then use the formula F=ma.

    EDIT:

    dokey, got b)

    (4i - 5j) + (pi + qj) = (i - 2j)

    4 + p = 1
    q - 5 = -2

    try to work from here
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    you have to times (i-2j) by k as it is parallel not equal...
    so basically its like
    4+p = k
    -5+q = -2k
    then u put them together and you'll get that answer
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    (Original post by tifflcy)
    you have to times (i-2j) by k as it is parallel not equal...
    so basically its like
    4+p = k
    -5+q = -2k
    then u put them together and you'll get that answer
    another five year old thread ...
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    (Original post by TeeEm)
    another five year old thread ...
    lol i was just looking for the answers when i was doin my hw then i figured it out
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    (Original post by tifflcy)
    lol i was just looking for the answers when i was doin my hw then i figured it out
    sure
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    Perhaps, like many equations where mass is equal to one, or slightly less than one, if you find some idea you can zero out, you are left with a binomial math problem, a choice between zero or one. My vote is that M, representing mass is less than or equal to one.
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    (Original post by Tellulater)
    Perhaps, like many equations where mass is equal to one, or slightly less than one, if you find some idea you can zero out, you are left with a binomial math problem, a choice between zero or one. My vote is that M, representing mass is less than or equal to one.
    This thread is 7 years old! Thread closed.
 
 
 
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