JEE Advance - Physics (2002 - No. 1)
An ideal spring with spring-constant k is hung from the ceiling and a block of mass M is attached to its lower end. The mass is released with the spring initially unstretched. Then the maximum extension in the spring is
$${{4Mg} \over k}$$
$${{2Mg} \over k}$$
$${{Mg} \over k}$$
$${{Mg} \over {2k}}$$