# An object with a mass of  2 kg is traveling in a circular path of a radius of 2 m. If the object's angular velocity changes from  2 Hz to  9 Hz in  1 s, what torque was applied to the object?

Torque $\tau = I \times \alpha = m {r}^{2} \times \frac{{w}_{2} - {w}_{1}}{t} = m {r}^{2} \times \frac{2 \pi \left({n}_{2} - {n}_{1}\right)}{t}$
$= 2 \times {2}^{2} \times 2 \times \pi \times \frac{9 - 2}{1} = 352 N m$