Answer: hello your question is incomplete below is the complete question
answer : Angular acceleration = 7.88 rad/s^2 ( clockwise )
minimum coefficient of friction = -0.2225
Explanation:
First step : we calculate acceleration at point O
a = rα
acceleration at point A
aA = ( 2r ) α = 2α
∑Fy ( force in y axis ) = mass of block * aA
∴ T = mBlock ( g - 2α )
= 8.7 ( 9.81 - 2α )
attached below is the remaining part of the solution