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!

Please help Motion problem

  1. Jan 18, 2006 #1
    Please help!! Motion problem

    Suppose one found the equation of a radial vector with respect to time.
    Then if one were to differentiate it with respct to time and find the value of r'(t=0)
    suppose that was value was positive then the velocity is positive
    if negaitve then the velocity is negative
    but what about the subsequent motion? keep in mind that the r(phi) where phi si the polar angle is given by an exp function.
    I understand that if r'(0) > 0 then it will proceed with positive displacement
    but hwat about the negative??

    this is a follow on from this question https://www.physicsforums.com/showthread.php?t=106913
     
  2. jcsd
  3. Jan 20, 2006 #2

    Tom Mattson

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I am confused by your question. Are you working in one dimension here? If so then the polar angle is fixed. And if not then it makes no sense to talk about the sign of the velocity. What is the sign of the [itex]\mathbb{R}^2[/itex] vector [itex]<-1,3>[/itex]? You can't define it because [itex]\mathbb{R}^2[/itex] vectors aren't ordered like the reals are.
     
  4. Jan 20, 2006 #3

    Tom Mattson

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    By the way stunner, these threads that you've been posting in Introductory Physics would acutally qualify as Advanced Physics, so I'm moving them. I think you will have better luck getting responses here.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Please help Motion problem
Loading...