A block with mass M is connected by a massless spring with stiffness constant k to a rigid wall and moves without friction on a horizontal surface. The block oscillates with small amplitude A about an equilibrium
position x₀. Consider two cases: (i) when the block is at x₀ ; and (ii) when the block is at x = x₀ + A. In both
the cases, a particle with mass m (< M) is softly placed on the block after which they stick to each other.
Which of the following statement(s) is (are) true about the motion after the mass m is placed on the mass
M?
(A) The amplitude of oscillation in the first case changes by a factor of, ⎷ M/ m+M, whereas in the second
case it remains unchanged
(B) The final time period of oscillation in both the cases is same
(C) The total energy decreases in both the cases
(D) The instantaneous speed at x₀ of the combined masses decreases in both the cases
