Answer:
The average angular acceleration is -2.628 rad/s²
Explanation:
Counterclockwise = positive
Clockwise = -negative
Given;
initial rotation of the flywheel, θ₁ = 6.55 rotation/s
final rotation of the flywheel, θ₂ = - 2.19 rotation/s
The average angular acceleration is given by;
[tex]\alpha = \frac{\delta \theta}{\delta t}\\\\ \alpha =\frac{\theta _2 - \theta_ 1}{t}\\\\ \alpha =\frac{-2.19 -6.55}{20.9} \\\\ \alpha =\frac{-8.74}{20.9}\\\\ \alpha = -0.4182 \ rotation / s^2\\\\ \alpha = \frac{-0.4182 \ rotation}{s^2}*\frac{2\pi \ radian}{rotation}\\\\ \alpha = -2.628 \ rad/s^2[/tex]
Therefore, the average angular acceleration is -2.628 rad/s²
