Let's begin by identifying key information given to us:
Radius (r) = 28 ft,
Plane Angle (θ) = 3 rev = 3 * 360° = 1080,
Time (t) = 1.5 min = (1.5 * 60) = 90 s,
Angular Speed (ω) = ?
[tex]\begin{gathered} AngularSpeed(\omega)=\frac{\theta}{t}=\frac{1080^{\circ}}{90}=12 \\ AngularSpeed(\omega)=12deg\text{/s} \end{gathered}[/tex]Hence, the angular speed is 12 degrees per second
