Two blocks A and B of the same mass are connected to a light spring and placed on a smooth horizontal surface B is given velocity `v_(0)` (as shown in the figure) when the spring is in natural length. In the subsequent motion.

Options

A. the maximum velocity of B will be `v_(0)`
B. as seen from ground, A can move towards right only
C. the spring will have maximum extension when A and B both stop
D. the spring will be at natural length again when B is at rest

Answer

A, B, D

Explanation

In CM frame the blocks will perform SHM as `[V_(CM)=v_(0)//2]`
:.` V_(CM)` is constant hence both will can have maximum velocity `v_(0)//2` towards right in CM frame.
:. `(v_(B))_(max)=v_(0)` in ground frame
in CM frame `(v_(A)_(min)=-v_(0)//2`
:. `(v_(A))_(min)=0` in ground frame
i.e. A move only in right direction In CM frame `v_(B)=v_(0)//2` left in the case when spring is at natural length
:.`v_(B)=0` in ground frame at that instant.