Final answer:
The net force on the refrigerator could be 200N if both men push in the same direction, or 0N if they push in opposite directions; the direction of the forces is needed to determine the exact net force.
Step-by-step explanation:
If both men are pushing on a refrigerator with a force of 100N in the same direction, the net force acting on the refrigerator would be the sum of both forces, resulting in a net force of 200N. But if they are pushing in opposite directions, the forces cancel each other out, and the net force on the refrigerator would be 0N. To determine the net force precisely, the direction of the forces applied by each man must be known. Without information about the direction, we cannot give a definitive answer.