A single mass m1 = 3.6 kg hangs from a spring in a motionless elevator. The spring is extended x = 15.0 cm from its unstretched length. . . Now, three masses m1 = 3.6 kg, m2 = 10.8 kg and m3 = 7.2 kg hang from three identical springs in a motionless elevator. The springs all have the same spring constant that you just calculated above. . . What is the distance the lower spring is stretched from its equilibrium length?