1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Vector forces.

  1. Aug 13, 2010 #1
    1. The problem statement, all variables and given/known data
    I got two forces acting on an object. I have the magnitude of the forces, 6 N and 2 N. Then i'm asked to find out what force is impossible to produce with these two forces.


    2. Relevant equations



    3. The attempt at a solution

    I have no idea where to begin with. Maybe i didn't think hard enough...
     
  2. jcsd
  3. Aug 13, 2010 #2
    Are you sure it's not just asking for an example of a force that can't be produced? This is a very weird question because the number of possible answers is infinite.
    Post the exact wording of the question.
     
  4. Aug 13, 2010 #3
    Theres a choice between 2N and 6N. Sorry. It's a multiple choice question. The other 2 answers are 8N and 4N which is quite obviously can be produced.
     
  5. Aug 13, 2010 #4
    Try drawing some triangles.You will see that only one of those vectors can be produced by adding the given vectors.
     
  6. Aug 13, 2010 #5
    It will be an isosceles triangle right ?
     
  7. Aug 13, 2010 #6
    Okay i found out the answers by using cosine rule. Are there some insights on this matter ? lol..
     
  8. Aug 13, 2010 #7
    Yes since you want to get either 6N or 2N using a 6N and a 2N.


    edit:
    The exercise is meant to teach you to watch out for answers that do no make sense.
     
    Last edited: Aug 13, 2010
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook