A long block A of mass M is at rest on a smooth horizontal surface. A small block B of mass M/2 is placed on A at one end and projected along A with same velocity v. The coefficient of friction between the block is μ. Then the acceleration of blocks A and B before reaching a common velocity will be respectively
The force causing the motion of A is a frictional force between A and B,
So, acceleration of A
Block B experiences frictions force towards the left.
MBaB = μMBg ⇒aB = μg towards left