Two block A and B of masses m and `2m` respectively are connected by a spring of spring cosntant k. The masses are moving to the right with a uniform velocity `v_(0)` each, the heavier mass leading the lighter one. The spring is of natural length during this motion. Block B collides head on with a thrid block C of mass `2m`. at rest, the collision being completely inelastic.

The velocity of centre of mass of system of block A, B, & C is -

Options

A. `v_(0)`
B. `(3v_(0))/(5)`
C. `(2v_(0))/(5)`
D. `(v_(0))/(2)`

Answer

(B)

Explanation

`v_(cm) = (mv_(0) + 2mv_(0))/(m + 2m + 2m) = (3v_(0))/(5)`