Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Vector addition

  1. Jun 5, 2005 #1
    Hi,

    The question is:

    The components of a vector V can be written as (V(x), V(y), V(z)). What are the components and length of a vector which is the sum of the two vectors, V(1) amd V(2). whose components are (8.0. -3.7,0.0) and (3.9,-8.1,-4.4)?

    Work

    For the components
    V(x)= 8.0+3.9=11.9
    V(y)=-3.7+-8.1=-11.8
    V(z)= 0+-4.4=-4.4


    That's all I have figured. I'm a little confused on the set up of this problem. to figure the length would I just use the Pythagorean theorem.

    Please help and thank you
     
  2. jcsd
  3. Jun 6, 2005 #2
    The magnitude of a vector is given by

    [tex] \sqrt{x^2+y^2+z^2} [/tex]
     
  4. Jun 6, 2005 #3
    So would the magnitude be

    V=((11.9)^2+(-11.8)^2+(-4.4)^2)^(1/2)
    V=(300.4)^(1/2)
    V=17.3

    Is this correct. Also when they refer to components the are referring to these:

    V(x)= 8.0+3.9=11.9
    V(y)=-3.7+-8.1=-11.8
    V(z)= 0+-4.4=-4.4

    Thank You
     
  5. Jun 6, 2005 #4
    yes, that's correct
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook