A plank with a small block on top of it is under going vertical SHM. Its period is 2s. The minimum amplitude at which the block will separate from plank is:
The block will
separate from plank if the maximum acceleration of SHM is more then
'g'. i.e. ω2A≥g
⇒A≥gω2 where ω=2πTs−1=2π2s−1=πs−1
⇒A≥gπ2
⇒A≥10π2 taking g=10m/s2