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: Power-law spiral

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

    Given L (angular momentum), find the form of V (r) so that the path of a particle is given by the spiral r = C(theta)k, where C and k are constants

    2. Relevant equations

    L = mr2(theta)'

    3. The attempt at a solution

    I know I have to find a expression for r' using no theta's and insert it into the energy formula E = K + V(r) but I am lost on how to apply it.
  2. jcsd
  3. Mar 10, 2009 #2
    Is that prime you have written on theta' in the angular momentum expression the time derivative of theta?

    If so, doesn't that give you a relation between r and theta-dot?
    The required trajectory is a relation between r and theta. Could you eliminate r between these two and do anything with that?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook