The four 5-lb spheres are rigidly attached to the crossbar frame having a negligible weigh...

The four 5-lb spheres are rigidly attached to the crossbar frame having a negligible weight. If a couple moment M = (0.5t + 0.8) lb • ft, where t is in seconds, is applied as shown, determine the speed of each of the spheres in 4 seconds starting from rest. Neglect the size of the spheres.