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Homework Help: Projectile Motion initial velocity

  1. Feb 6, 2005 #1
    Consider a particle with initial velocity [tex]v[/tex] that has magnitude 12.0m/s and is directed 60.0 degrees above the negative x axis.

    1.) What is the x component [tex]v_x[/tex] of [tex]v[/tex](velocity)?

    Express your answer in meters per second.

    a.) [tex]v_x = ____[/tex]

    well i drew the picture where the negative x-axis was located, and did sin(60)*12 = 10.392, but since it's where the negative x-axis is, it'll be -10.392 right?

    2.) What is the y component [tex]v_y[/tex] of [tex]v[/tex](velocity)?
    a.) [tex]v_y = ____[/tex]

    well i kinda did the same thing as for the first question, cos(60)*12 = 6m/s

    are these two correct?
     
  2. jcsd
  3. Feb 6, 2005 #2

    dextercioby

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    With the angles reversed,they are... :wink: Pay attention at that triangle...


    Daniel.
     
  4. Feb 6, 2005 #3
    what do you mean by reversing the angles? so instead of 60, you mean i should use -60?
     
  5. Feb 6, 2005 #4

    dextercioby

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    No,no.The "x" component needs to be gotten with a cosine and the "y" with a sine...Basically just reverse of what u did...

    Daniel.
     
  6. Feb 7, 2005 #5
    ah thanks for the help, i had my triangle label incorrectly by mistake
     
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