#### Answer

$w=0.1803$ radian per sec

#### Work Step by Step

Step 1: The formula to be used here is $w=\frac{\theta}{t}$.
Step 2: After substituting the values of $\theta$ and $t$ provided by the question into this formula, the equation becomes $w=\frac{3.871}{21.47}$
Step 3: Solving, $w=0.1803$ radian per sec