question_answer

A particle of mass m is attached to M via a massless string passing through a hole O in the horizontal table as shown. Mass M is kept stationary whereas mass m is rotating in a circle of radius r with angular speed g).

A) \[Mg=mr{{\omega }^{2}}\]                  

B) \[Mg>mr{{\omega }^{2}}\]

C) \[Mg<mr{{\omega }^{2}}\]                  

D) \[Mg\ge mr{{\omega }^{2}}\]

Correct Answer: A

Solution :

[a] Tension provide the necessary centripetal force \[T=m\,{{\omega }^{2}}=Mg\] \[m\,{{\omega }^{2}}r=Mg\]