A mass m is fixed to the lower most point of spring kept in vertical direction which is stretched slowly by a length . When the system comes to equilibrium. If this arrangement has a sudden fall of mass what can be maximum stretch ?
In slow operation, weight acts on the centre of gravity of the spring.
In free fall the same weight acts at the lower most end of the spring. The same spring can now have change in length double, i.e., 2l.