Question : A particle of mass π is initially situated at the point π inside a hemispherical surface of radius π as shown in figure. A horizontal acceleration of magnitude π0is suddenly produced on the particle in the horizontal direction. If gravitational acceleration is neglected, the time taken by particle to touch the sphere again is
(A) \sqrt{\dfrac{4r\sin \alpha }{a_{0}}}
(B) \sqrt{\dfrac{4r\tan \alpha }{a_{0}}}
(C) \sqrt{\dfrac{4r\cos \alpha }{a_{0}}}
(D) none of these
Answer : option (C)
Solution :

