A grindstone, initially at rest, is given a constant angular acceleration so that it makes 20.0 rev in the first 8.00 s. What is its angular acceleration?
(a) 0.313 rad/s2 (c) 2.50 rad/s2 (e) 3.93 rad/s2
(b) 0.625 rad/s2 (d) 1.97 rad/s2
Rotational Kinematic equations
The Attempt at a Solution
Ok so I am using the equation ω = ω (initial) + ∝ T
BUT my answer is the wrong one. It seems that I have to use this equation ω^2 = ω (initial) ^2 + 2∝Θ
but what do I put in liew of "Θ"??????
I just don't understand why is that I have to use that equation?