question_answer

A block is kept on a frictionless inclined surface with angle of inclination 'a'. The incline is given an acceleration 'a' to keep the block stationary. Then a is equal to       [AIEEE 2005]

A)             \[g\]

B)             \[g\,tan\alpha \]

C)             \[g/\,tan\alpha \]

D)             \[g\,cosec\alpha \]

Correct Answer: B

Solution :

    Let the mass of a block is m. It will remains stationary if forces acting on it are in equilibrium i.e, \[ma\cos \alpha =mg\sin \alpha \]Þ \[a=g\tan \alpha \]                                          Here \[ma\] = Pseudo force on block, mg = Weight.