1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

Spinning and heating a metal rod

  1. Oct 3, 2012 #1
    1. The problem statement, all variables and given/known data
    There's a metallic rod of length l1 which is spinning around a vertical ax which passes through its center. The ends of the rod are spinning with ω1 angular speed.

    2. Relevant equations
    Determine the temperature at which to heat the metal rod so that the angular speed of the end ω2 doubles.
    Also, how to generally approach problems involving torque or angular momentum? (How to figure out when to use them, and how to use the formulas/equations in order to solve the problem.)

    3. The attempt at a solution
    The only idea I have is the following: ω1 and ω2 are constant, so the net force is 0, and so the angular momentum r⃗ ×mv⃗ is conserved. How should I approach this? And in general, for problems relating to torque or angular momentum, how should I approach those?
  2. jcsd
  3. Oct 3, 2012 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook