Aglider with mass m = 0.250kg sits on a frictionless horizontal air track, connected to a spring with force constant k = 4.60 n/m . you pull on the glider, stretching the spring 0.100 m , and then release it with no initial velocity. the glider begins to move back toward its equilibrium position (x=0).a) what is the speed of the glider when it returns to ? b) what must the initial displacement of the glider be if its maximum speed in the subsequent motion is to be 2.60 ?