In each paragraph 3 multiple choice questions are given. Each of these questions has four choices (A), (B), (C) and (D) out of which ONLY ONE is correct.
A small block of mass M moves on a frictionless surface of an inclined plane, as shown in figure. The angle of the incline suddenly changes from 60∘ to 30∘ at a point B. The block is initially at rest at A. Assume that collisions between the block and the incline are totally inelastic (g=10m/s2)S
The speed of the block at a point B immediately after it strikes the second incline is