Answer:
3.6 rad/s
Step-by-step explanation:
Given that,
Radius of a compact disc is 6 cm
The angular acceleration of the disc is 1.2 rad/s²
Time, t = 3 seconds
We ned to find the angular velocity of the disc once it is at full speed. The relation between the angular velocity and angular acceleration is given as follows :
![\alpha =(\omega)/(t)\\\\\because\ \omega=\text{angular velocity}\\\\\omega=\alpha t\\\\\omega=1.2* 3\\\\\omega=3.6\ rad/s](https://img.qammunity.org/2021/formulas/physics/high-school/c12junl1b8evzqbvnwl2byll9hc9muywef.png)
So, the angular velocity of the disc is 3.6 rad/s.