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: Magnitude of Torque

  1. Mar 25, 2008 #1
    1. The problem statement, all variables and given/known data

    Massive spinning flywheels (disks) can be used for storing energy. Consider a flywheel with a diameter of 1.10 m and a mass of 510 kg. A constant force of magnitude F is applied tangentially to the rim of the flywheel to accelerate it from rest to 4.00 x 103 rev/min during 2.85 min.

    (b) What magnitude of torque is necessary to cause this angular acceleration?

    2. Relevant equations

    I = mR[tex]^{2}[/tex]
    [tex]\tau[/tex] = I[tex]\alpha[/tex]

    3. The attempt at a solution

    I = mR[tex]^{2}[/tex]
    I = (510kg)[tex]\ast[/tex](.55m)[tex]^{2}[/tex]
    I = 154.275 kgm[tex]^{2}[/tex]

    [tex]\tau[/tex] = I[tex]\alpha[/tex]
    [tex]\tau[/tex] = (154.275kgm[tex]^{2}[/tex])\ast(2.449rad/s[tex]^{2}[/tex]
    [tex]\tau[/tex] = 377.819 Nm

    The answer was incorrect. Also the angular acceleration was derived from part a and is the correct number. Thanks for the help.
  2. jcsd
  3. Mar 25, 2008 #2
    the Tau and Alpha symbols are not suppose to be superscripts. i screwed up the tex
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook