An overnight rainstorm has caused a major roadblock. Three massive rocks of mass m1 = 584 kg, m2 = 815 kg and m3 = 355 kg have blocked a busy road. The rocks are side by side blocking the road and lined up from left to right in order as m1, m2 and m3. The city calls a local contractor to use a bulldozer to clear the road. The bulldozer applies a constant force to m1 to slide the rocks off the road. Assuming the road is a flat frictionless surface and the rocks are all in contact, what force, FA, must be applied to m1 to slowly accelerate the group of rocks from the road at 0.250 m/s2?

FA____N

Use the value found above for FA to find the force, F12, exerted by the first rock of mass 584 kg on the middle rock of 815 kg.

F12____N