Calculate Magnitude of Torque for Flywheel

[sealedhuman77]

Homework Statement

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?

Homework Equations

I = mR^{2}
\tau = I\alpha

The Attempt at a Solution

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

\tau = I\alpha
\tau = (154.275kgm^{2})\ast(2.449rad/s^{2}
\tau = 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.

 

[sealedhuman77]

the Tau and Alpha symbols are not suppose to be superscripts. i screwed up the tex