A glider of mass 0.150 kg moves on a horizontal frictionless air track. It is permanently attached to one end of a mass less horizontal spring, which has a force constant of 10.0 N/m both for extension and for compression. The other end of the spring is fixed. The glider is moved to compress the spring by 0.180 m and then released from rest. Calculate the speed of the glider (a) At the point where it has moved 0.180 m from its starting point, so that the spring is momentarily exerting no force and (b) At the point where it has moved 0.250 m from its starting point.