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: Angular acceleration of a solid uniform cylinder

  1. Nov 30, 2009 #1
    String is wrapped around the outer rim of a solid uniform cylinder that is free to rotate about a frictionless axle through its center. When the string is pulled with a force P tangent to the rim it gives the cylinder an angular acceleration alpha. If the cylinder had twice the radius, but everything else was the same, the angular acceleration would be
    A) 4*alpha
    B) 2*alpha
    C) alpha/2
    D) alpha/4

    Wouldn't it be 4 times, since the diameter is now four times as large?
  2. jcsd
  3. Nov 30, 2009 #2


    Staff: Mentor

    If the radius is doubled, the diameter is also doubled, not quadrupled.
  4. Nov 30, 2009 #3
    Oh right, haha. So would it just be 2*alpha or is this a trick question?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook