An ideal spring of spring constant k, is suspended from the ceiling of a room and a block of mass M is fastened to its lower end. If the block is released when the spring is un-stretched, then the maximum extension in the spring is
A. 4 Mg/k
B. Mg/k
C. 2 Mg/k
D. Mg/2k
Answer:C
An ideal spring of spring constant k, is suspended from the ceiling of a room and a block of mass M is fastened to its lower end. If the block is released when the spring is un-stretched, then the maximum extension in the spring is
A. 4 Mg/k B. Mg/k C. 2 Mg/k D. Mg/2k