The angular speed of a fly wheel moving with uniform angular acceleration changes from 1200 rpm to 3120 rpm in 16 seconds. The angular acceleration in rad/s2 is :

2 \(\pi\) 4 \(\pi\) 12 \(\pi\) 104 \(\pi\)

4 \(\pi\)

Angular acceleration : \(\alpha\) = \(\frac{\omega_f - \omega_i}{t}\) \(\omega\)f = 3120 x \(\frac{2 \pi}{60}\) rad/s \(\omega\)i = 1200 x \(\frac{2 \pi}{60}\) rad/s t = 16 s \(\alpha\) = 4 \(\pi\)