A block having mass M is placed on a horizontal frictionless surface. This mass is attached to one end of a spring having force constant k. The other end of the spring is attached to a rigid wall. This system consisting of spring and mass M is executing SHM with amplitude A and frequency f. When the block is passing through the mid-point of its path of motion, a body of mass mis placed on top of it, as a result of which its amplitude and frequency changes to A’ and f’. If the velocity before putting the mass and after putting it is $ \nu $ and $ \nu ' $ respectively, then $ { \nu' \over \nu } $=...................................
According to the law of conservation of momentum, $ MV = (M + m) \nu ' $