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    Forces P, Q and R act on a particle at the origon O. find the magnituide of the resultant and the angle it makes with Ox.

    a) P= 2i + 5j
    Q= 3i + 4j
    R = 5i + 2j

    i know to find the manitutde of the reusltant, you use phytag, and to find the angle its normally Tan x = opp/adj

    but how do you do this with the i and j??

    Thanks.
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    Well what are i and j? They are the unit vectors in the x and y direction. So you know that you have a vector that has magnitude 10 in the x-direction, and magnitude 11 in the y-direction. What triangle do these two components give, and what is the angle made with the Ox?
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    (Original post by Kolya)
    Well what are i and j? They are the unit vectors in the x and y direction. So you know that you have a vector that has magnitude 10 in the x-direction, and magnitude 11 in the y-direction. What triangle do these two components give, and what is the angle made with the Ox?
    oh right, i only thought to use phytag for the reusltant only! so we use it the same way for all 2 sides of the right angle triange and then use trig?
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    I don't know what "phytag" is.
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    (Original post by Kolya)
    I don't know what "phytag" is.
    pythag?
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    Just use tan(t)= o/a , as you said...
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    (Original post by Kolya)
    Just use tan(t)= o/a , as you said...
    ok, thanks a lot!
 
 
 
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