An ideal spring of spring constant k, is suspended from the ceiling of a room and a blok of mass m is fastened to its lower end. If the block is released when the spring is un-stretched, then then maximum extension in the spring is :

An ideal spring of spring constant k, is suspended from the ceiling of

1.	An ideal spring of spring constant k, is suspended from the ceiling of a room and a blok of mass m is fastened to its lower end. If the block is released when the spring is un-stretched, then then maximum extension in the spring is :
Answer» `4(Mg)/(k)` `(Mg)/(k)` `2(Mg)/(k)` `(Mg)/(2k)` Solution :Workdone by gravity + Workdone by SPRING = Change in KINETIC energy `MGX+(-(1)/(2)kx^(2))=0` `Mgx=(1)/(2)kx^(2)` `Mg=(kx)/(2)implies therefore X=(2Mg)/(k)`