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!

Net torque! Need help with angular acceleration.

  1. Dec 8, 2009 #1
    1. The problem statement, all variables and given/known data
    A certain wheel has a rotational inertia of 12 kg m2. As it turns through 5.0 rev its angular velocity increases from 5.0 rad/s to 6.0 rad/s. If the net torque is constant, its value is:

    2. Relevant equations
    Angular acceleration = dW/dT
    Net torque = (angular acceleration)*(rotational inertia)
    Θf = Θi + (Wi)(dT) + [tex]\frac{1}{2}[/tex] [tex]\alpha[/tex][tex]\Delta[/tex]t2

    3. The attempt at a solution
    I have dW = 5-6=-1rad/s
    I am confused on how to find dT. The equations have have both have two unknowns (t & [tex]\alpha[/tex])
    Last edited: Dec 8, 2009
  2. jcsd
  3. Dec 8, 2009 #2
    why dont you try this formula:

    (wf)^2 - (w0)^2 = 2 alpha * omega.
  4. Dec 10, 2009 #3
    Thank you so much! That worked. I'm glad you had that equation. I did not, and it happened to be on the test.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook