In order to calculate the angular acceleration, we can use the following formula:
[tex]a=\frac{v_f-v_i}{t}[/tex]Where vf is the final angular speed, vi is the initial angular speed and t is the interval of time.
Since the speed is in rev/min, we need to convert to rad/s.
Knowing that 1 rev = 2π rad and 1 min = 60 s, we have:
[tex]\begin{gathered} 33\text{ rev/min}=33\cdot\frac{2\pi\text{ rad}}{60\text{ s}}=3.456\text{ rad/s} \\ 11\text{ rev/min}=11\cdot\frac{2\pi\text{ rad}}{60\text{ s}}=1.152\text{ rad/s} \end{gathered}[/tex]Now, using vf = 1.152, vi = 3.456 and t = 2, we have:
[tex]a=\frac{1.152-3.456}{2}=\frac{-2.304}{2}=-1.152\text{ rad/s2}[/tex]So the angular acceleration is -1.152 rad/s².
