Physics question II2

when the mass is put on the top of spring, it gains potential energy. once it falls down, the potential energy will transfer into mechanical energy. as there is a spring below it, the spring will be forced to compressed and resulted in gain of the strain energy transferred from the mechanical energy of the mass. after the spring reaches the equibrilium, i.e. the gravity force of the mass equals to the upward reaction force of the spring, the string will transfer its strain energy to the mechanical energy of the mass and causing the mass moving upwards. if there is no energy loss in the system, the above motions will continue forever. in reality due to the existence of energy loss to the internal energy or other form of energy, the above motions will gradually become to a smaller manner and finally stop at the equibrilium point.