The spring constant is k = 850 N/m, mA = 40 kg, and mB = 60 kg. The collar A slides on the...

The spring constant is k = 850 N/m, mA = 40 kg, and mB = 60 kg. The collar A slides on the smooth horizontal bar. The system is released from rest in the position shown with the spring unstretched. Use conservation of energy to determine the velocity of the collar A when it has moved 0.5 m to the right.