question_answer

A stone is attached to one end of a string and rotated in a vertical circle. If string breaks at the position of maximum tension, it will break at

A) \[A\]                                     

B) \[B\]

C) \[C\]                                     

D) \[D\]

Correct Answer: B

Solution :

The body is describing a vertical circle, \[\therefore \]  \[T-mg\cos \theta =\frac{m{{v}^{2}}}{l}\] or            \[T=mg\cos \theta +\frac{m{{v}^{2}}}{l}\] Tension is maximum when \[\cos \theta =+1\] and velocity is maximum. Both condition are satisfied at\[\theta ={{0}^{o}}\](ie, at lowest point\[B\]).