Step 1:
\(a)
\The angular velocity of the phonograph turntable is
.
The distance from the axis of rotation is
.
Convert the angular velocity from rev/min to rad/sec.
\
Find the angular acceleration.
\Angular acceleration :
,
where
is the distance from the center of axis.
is the angular velocity.

Angular acceleration of the block is
.
Solution:
\Angular acceleration of the block is
.
\

Step 1:
\(b)
\The block exerts a force equal to the force due to friction.
\
Coefficient of static friction is 0.06837.
\Solution:
\Coefficient of static friction is 0.06837.
\\
\
Step 1:
\(c)
\The angular velocity of the phonograph turntable starts from rest.
\Velocity reaches
in 0.25 sec.
Angular velocity : 
The distance from the axis of rotation is
.
Find the angular acceleration.
\Angular acceleration :
,
where
is the distance from the center of axis.
is the angular acceleration.

Step 2:
\Total angular acceleration.
\
Total acceleration of the block is
.
Solution:
\Angular acceleration of the block is
.
\
\
\
Step 1:
\(d)
\The block exerts a force equal to the force due to friction.
\
Coefficient of static friction is 0.10399.
\Solution:
\Coefficient of static friction is 0.10399.