Question

A turbine fan in a jet engine has moment of inertia $2.5kg$ $m^2$ about its axis of rotation. Its angular velocity is $40t^2$. Find the net torque at any instant.

• A. $100t$
• B. $100t^2$
• C. $200t$
• D. $200t^2$

Answer 1

The correct option is C $200t$

$\tau =\frac{dL}{dt}=\frac{d}{dt}\left(I\omega \right)=\frac{d}{dt}(2.5\times 40t^2)$

$\tau =200t$