A set of n identical cubical blocks lies at rest parallel to each other along a line on a smooth horizontal surface. The separation between the near surfaces of any two adjacent blocks is L . The block at one end is given a speed v towards the next one at time 0 t . All collisions are completely inelastic, then
A. The last block starts moving at `t=((n-1)L)/(v)`
B. The last block starts moving at `t=(n(n-1)L)/(2v)`
C. the centre of mass of the system will have a final speed v
D. The centre of mass of the system will have a final speed `(v)/(n)`.
