Answer:
The angular speed of the disc be at this time is 46.65 rad/s.
Step-by-step explanation:
Given that,
Angular acceleration
![\alpha= 3.11\ rad/s^2](https://img.qammunity.org/2020/formulas/physics/college/4kxbs8i5w5yy6ooj86p3s5h6lupdv9ccsy.png)
Time t =15.0 s
We will calculate the angular speed of the disc
A disc initially at rest.
So,
![\omega=0](https://img.qammunity.org/2020/formulas/physics/college/gkgdsi9onkvj67ijkynsdlgc59b9g288tk.png)
Using rotational kinematics equation
![\omega'=\omega+\alpha\ t](https://img.qammunity.org/2020/formulas/physics/college/9jpd1nb2y7ykys5ggzej7isxdhdjds8pun.png)
Where,
= initial angular speed
=final angular speed
= angular acceleration
Put the value in the equation
![\omega'=0+3.11*15](https://img.qammunity.org/2020/formulas/physics/college/2r1f6ut4dxx2at9bl0vp06ljzi87t6mk7v.png)
![\omega'=46.65\ rad/s](https://img.qammunity.org/2020/formulas/physics/college/hzqx1cnq1cgsrf6ai5nushpg0wgkvurpcw.png)
Hence, The angular speed of the disc be at this time is 46.65 rad/s.