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Homework Help: How do i solve this physics problem that contains vectors

  1. Oct 6, 2008 #1
    1. The problem statement, all variables and given/known data
    Each of the displacement vectors A and B have a magnitude of 3.00.
    Vector B lies on the y axis and Vector A has a 30 degree angle from the positive X axis.

    a) A+B
    magnitude = ?
    θ = ?

    (b) A-B
    magnitude = ?
    θ= ? °

    (c) B - A
    magnitude =?
    θ= ? °

    (d) A - 2B
    magnitude =?
    θ= ? °

    2. Relevant equations

    3. The attempt at a solution

    I really dont have a clue how to figure this out, any help would be great
  2. jcsd
  3. Oct 13, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper

    The idea is, when adding vectors, to separate them into their components, and then add those components to make the new vector. You know [tex]\vec{B}=3\hat{y}[/tex], and [tex]\vec{A}=3\cos{30}\hat{x} + 3\sin{30}\hat{y}[/tex], at least you should know that. So then, for example, [tex]A + B = 3\cos{30}\hat{x} + (3 + 3\sin{30})\hat{y}[/tex]. Make sense? See where you can get using this method.
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