sir,if in any question a block comes down an inclined plane having inclination of sixty degree it reaches a pointA where it undergoes oblique inelastic collision with inclined plane and at this point angle of inclination of plane changes to thirty degrees ,then how can the perpendicular component of velocity of blocki.e,component of velocity perpendicularto the inclined plane at that point be zero

Dear Abishiek,

Can you be more clear in ur questions please.. Becuse u have mentioned that the block comes down the inclines plane  and undergoes inelastic collision with the inclined plne.. How is possible for the body sliding along the inclined plane will undergo go collision with the inclines plane its selve..

So, next time post ur question with diagrams for better understanding of the problem and it would be more easy for us to solve.

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