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

Direction of frictional force

  1. Mar 17, 2009 #1
    1. The problem statement, all variables and given/known data

    "Friction hinders translation but aids rotation"
    If a uniform disc is placed on a surface and a force is applied tangential to it, why is the direction of friction same as that of the force. This would surely hinder rotation and aid translation, right?

    2. Relevant equations

    This is not a problem.

    3. The attempt at a solution
    Out of ideas. Thought a lot about it.
  2. jcsd
  3. Mar 17, 2009 #2
    I believe what they are trying to say is when the disk spins, it is pushing the surface in the opposite direction of which it is moving. Think about it: when you push against the ground, you move in the opposite direction of your push. Therefore, the friction is in the opposite direction of which it is spinning.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook