Question

A0.12-m-radius grinding wheel takes 5.5 s to speed up from 2.0 rad's to 11.0 rad/s. What is the wheel's average angular acceleration? a. 9.6 rad's b. 4.8 radis c. 1.6 rad/s d. 0.33 rad/s

Answer 1

Answer:

The correct answer is option 'c': $1.6rad/s^{2}$

Explanation:

By definition of angular acceleration we have

$\alpha =\frac{\omega _{f}-\omega _{i}}{t_{f}-t_{i}}$

where,

$\omega _{f}$ is the final angular velocity

$\omega _{i}$ is the initial angular velocity

${t_{f}-t_{i}$ is the time in which the angular velocity is changed

Applying values we get

$\alpha =\frac{11-2}{5.5}\\\\\therefore \alpha =1.63rad/s^{2}$