Question

Your concave plate with a mass of 2 kg is spinning on top the table with a velocity of 1.5
rad/s for 2 seconds then your brother came and spins it more creating a velocity of 4 rad/s
for 6 seconds. What is the angular acceleration of your concave when you are spinning it
and the angular acceleration after your brother spins it?

Answer 1

$$a_1=\frac{v_1}{t_1}=\frac{1.5}{2}=0.75\frac{m}{s^2}$$

$$a_2=\frac{v_2-v_1}{t_2}=\frac{4-1.5}{6}=0.42\frac{m}{s^2}$$