A Yo-Yo of mass m has an axle of radius b and a spool of radius R. The Yo-Yo is placed upright on a table and string is pulled with a horizontal force vecF to the right as shown in figure. The static friction coefficient between Yo-Yo and table is mu_(s). Now there are two cases. case (a): The string is pulled very gently? case (b): The string is jerked hard?

A Yo-Yo of mass m has an axle of radius b and a spool of radius R. The

1.	A Yo-Yo of mass m has an axle of radius b and a spool of radius R. The Yo-Yo is placed upright on a table and string is pulled with a horizontal force vecF to the right as shown in figure. The static friction coefficient between Yo-Yo and table is mu_(s). Now there are two cases. case (a): The string is pulled very gently? case (b): The string is jerked hard?
Answer» Clockwise in CASE (a) Anticlockwise in case (a) Clockwise in case (b) Anticlockwise in case (b) SOLUTION :In first case, we can WRITE torque equation about point because it COINCIDES with INSTANTANEOUS axis of rotation while in second case, you will write torque equation of centre of mass.

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