# An object with a mass of  7 kg is traveling in a circular path of a radius of 9 m. If the object's angular velocity changes from  5 Hz to  1 Hz in  8 s, what torque was applied to the object?

Jan 28, 2016

-283.5Nm

#### Explanation:

we know,
$\tau = I \alpha$
=mr^2(deltaomega)/(deltat
$= m {r}^{2} \frac{{\omega}_{2} - {\omega}_{1}}{\delta t}$
$= 7 \cdot {9}^{2} \frac{1 - 5}{8}$
$= 567 \cdot \frac{- 4}{8}$
$= - 283.5 N m$