An ideal massless spring S can be compressed 1  m by a force of 100N in equilibrium .The same spring is placed at the bottom of a frictionless inclined plane at 30o to the horizontal. A 10kg block M is releases from rest at the top of the incline and is brought to rest momentarily after compressing the spring by 2m. If g = 10 ms-2, what is the speed of mass just before it touches the spring?