1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Simple Vector Problem - Finding the x-component

  1. Jun 10, 2009 #1
    1. The problem statement, all variables and given/known data

    A velocity vector 45 below the positive x-axis has a y-component of - 29 .
    What is the value of its x-component?

    2. Relevant equations

    Vx = |V|Cos(Theta)
    Vy = |v|Sin(Theta)

    3. The attempt at a solution

    Theta = -45 degrees
    y-component: -29 = xSin(-45) .... where x is the magnitude of the vector

    x = Sin(-45) / - 29
    ...x = 0.2438

    So |V| = 0.24~

    Vx = (0.24)Cos(-45)
    ...=0.171

    Says it's wrong, and I dont know where to go now. Am a bit embarassed asking for help with a simple problem like this :\
     
  2. jcsd
  3. Jun 10, 2009 #2
    Oops sorry, nevermind, I realised that in Step 2 I should have divided by Sin(-45)

    apologies!
     
  4. Jun 10, 2009 #3
    1. The problem statement, all variables and given/known data

    Find x- and y-components of the following vectors
    v = 7.0 cm/s, negative x-direction

    2. Relevant equations

    Vx = |V|Cos(Theta)
    Vy = |v|Sin(Theta)

    3. The attempt at a solution

    I'm a bit stuck here. I slotted in 7cm/s for |v| but how do I find the components if I'm not given an angle or graphical representation?
     
  5. Jun 10, 2009 #4

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    It says 'negative x direction'. I think that means it points along the x-axis in the, uh, 'negative' direction. Are you sure you don't want to rethink posting this question?
     
  6. Jun 10, 2009 #5
    I thought of that after I posted it and came up with -1, 0 as the x,y components [using cos180 and sign 180) which was still wrong. it's late so I wasn't thinking clearly :P
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Simple Vector Problem - Finding the x-component
  1. Vectors (x/y-components) (Replies: 14)

Loading...