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General
Easy
Question
In rotational motion if angular acceleration (or retardation) is constant we can apply equations of motion 
= 
etc. Here 
= 
A solid sphere of mass 5 kg and radius 1 m after rotating with angular speed 
= 40 rad/s is placed between two smooth walls on a rough ground. Distance between the walls is slightly greater than the diameter of the sphere. Coefficient of friction between the sphere and the ground is 
= 0.1. Sphere will stop rotating after time t = ......... s:
- 8
- 12
- 20
- 16
The correct answer is: 16
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