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Homework Help: Magnitude of the vector r=r2−r1?

  1. Jan 29, 2010 #1
    1. The problem statement, all variables and given/known data

    Consider the two vectors r1 and r2 . The magnitudes of the two vectors are: r1=5.9 and r2=8.5. The vectors directions relative to the x axis are defined by the angles: θ1=37 degrees and θ2=65 degrees.

    What is the magnitude of the vector r=r2−r1?

    What is the angle between r and the x axis? (in degrees)

    2. Relevant equations
    Break each vector into components: x1, y1, x2, y2, then consider the vector r as (x2-x1,y2-y1)

    3. The attempt at a solution

    Break each vector into components: x1, y1, x2, y2, then consider the vector r as (x2-x1,y2-y1)

    So broke each vector into triangles and calculated the x-component & y= components:
    R1 x component: tan37deg=3.55/x= 4.73 N
    R1 y component: sin37deg= y1/5.9=3.55 N
    R2 x component: tan65=7.7/x=3.59
    R2 y component: sin65=y2/8.5

    then i got stuck here... help me out please?
    Last edited: Jan 29, 2010
  2. jcsd
  3. Jan 29, 2010 #2


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    Homework Helper

    Now that you have x1, y1, x2, and y2, why can't you write the vector as (x2-x1,y2-y1)?
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