Hi there!
a)
We can find the angular velocity at t = 2.0 s by plugging in this value into the equation.
[tex]\omega (t) = 25.0t \\\\\omega (2) = 25.0(2) = \boxed{50.0 \frac{rad}{s}}[/tex]
b)
The angular acceleration is the derivative of the angular velocity, so:
[tex]\alpha (t) = \frac{d\omega}{dt} (25.0t) = 25.0[/tex]
Thus, the angular acceleration is a constant 25 rad/s².
