Answer:

Step-by-step explanation:
From the question we are told that:
Mass 

Radius 

Angular velocity 

Radial force of 

Kinetic coefficient of friction 

Generally the equation for Kinetic Force is mathematically given by
 

 

 

Generally the equation for Torque on Center is mathematically given by
 

Where 
 

Therefore
 

 

 

Therefore Angular acceleration of the grindstone is
