question_answer

A fighter plane is moving in a vertical circle of radius ?r?.  Its minimum velocity at the highest point of the circle will be                                     [MP PET 2000]

A)             \[\sqrt{3\,g\,r}\]

B)                     \[\sqrt{2\,g\,r}\]

C)             \[\sqrt{g\,r}\]   

D)             \[\sqrt{gr/2}\]