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!

Rolling motion

  1. Nov 30, 2014 #1
    How does friction affect the type of rolling motion of an object. For instance, does having more friction than the required friction for rolling cause the object to spin?
  2. jcsd
  3. Nov 30, 2014 #2
    Friction is the resistance to motion. Force is required to overcome resistance then acceleration occurs and friction increases.
  4. Nov 30, 2014 #3
    I think you misunderstood me. A typical example is a ball rolling down an igloo from the top. The friction changes as it goes along the surface. So, when the ball starts sliding, is the friction less than or greater than required friction for rolling?
  5. Nov 30, 2014 #4
    Now I think I understand your question... the line between rolling and sliding, would vary greatly depending I think mostly on the mass of the ball then on the rolling resistance versus the sliding resistance which would be less to slide or more to roll. Similar to a car skidding on ice, braking increases rolling resistance.
  6. Nov 30, 2014 #5
    Correct me if i am wrong: The ball would spin (rotational>linear) if friction>required OR slid (linear>rotational) if friction<required. Finally, the ball would pure roll (vcm=rw) if friction=required.
  7. Dec 1, 2014 #6
    It would be a razor sharp line where rolling friction = sliding friction... it is a dynamic situation, any way I think about it there is not a way to maintain a balance there. Even if the ball starts on a surface where these frictions are balanced, sliding would cause some rolling or rolling would cause some sliding. No matter what the ball is going down its just which ever the least resistive way to get there is.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook