Two smooth blocks of same mass are connected by an inextensible and massless string which is passing over a smooth Pulley are kept in a lift the lift is going down with acceleration a what should be the value of a in metre per second square so that acceleration of block a with respect to ground will be minimum

Dear student,

When lift is moving down with acceleration, each of the blocks will experience a pseudo force upwards equal to. Hence the effective acceleration due to gravity will becomes. Since the effective weight of both the blocks will be lesser but still be equal to that of each other, the net acceleration of block will also be zero because the tension will try to balance the effective weight of each of them. But this is the case in frame of the lift.

In the frame of ground, thus, the acceleration will be equal to that of the lift. Hence for minimum value of acceleration of the lift would be acceleration of block with respect to ground will be minimum, which woud be when the lift is not accelerated at all.