Two small balls A and B are made of same material, A is solid but B is hollow. These are connected by an ideal spring and this system is kept over a smooth plank such that center of mass of two balls coincide with mid point of the plank. Initially the spring is compressed by a certain amount and the plank is in horizontal position. Now we release the system then, 
according to the given question ,
in the question only it is given that center of mass of body are coinciding with mid point of plank,therefore with respect to the condition of equilibrium,these bodies will be at constant point only.
plank will not rotate
A block of mass m is attached with a spring of force constant k. The block is kept on a frictionless plank. The other end of the spring is connected with the plank. Mass of the plank is M and it is also kept on a frictionless surface.
Initially, the system is stationary. A sharp impulse P is applied on the block as shown. The maximum compression in the spring will be
Two blocks of masses m1 and m2 are connected with a light spring and placed over a plank moving with an acceleration a as shown in figure. The coefficient of friction between the blocks and plank is μ. The spring will
A plank of mass 5 kg is placed on a frictionless horizontal plane. Further a block of mass 1 kg is placed over the plank. A massless spring of natural length 2 m is fixed to the plank by its one end. The other end of spring is compressed by the block by half of spring's natural length. The system is now released from the rest, velocity of the plank when block leaves the plank is
[Assume, there is no friction between the two blocks]
A spring is connected with plank and other end of spring is connected with a block of mass m. Initially spring is stretched by a distance x0 and block is connected with a thread which is connected to other end of the plank as shown. If thread is cut, what will be maximum speed of the plank.
Two men 'A' and 'B' are standing on a plank. 'B' is at the middle of the plank and 'A' is at the left end of the plank. The lower surface of the plank is smooth. The system is initially at rest and masses are as shown in the figure. 'A' and 'B' start moving such that the position of 'B' remains fixed with respect to ground. A and B meets at some position. Then the point where A meets B is located at