Two blocks of different masses are attached to a spring and the system is kept on a smooth horizontal surface. Now if any of the blocks is given a sharp impulse, what will be the motion of centre of mass (COM) of the system with respect to ground after a long time

• A

  the COM will continue to accelerate

• B

  the COM will eventually come to rest

• C

  the COM will continue to move with constant speed

• D

  the COM will first accelerate then will suddenly come to rest