In the image, a box is subjected to two forces: 50 N to the left and 50 N to the right. Since these forces are equal in magnitude but opposite in direction, they cancel each other out. Therefore, the net force on the box is:

$\text{Net force} = 50 \, \text{N (right)} - 50 \, \text{N (left)} = 0 \, \text{N}.$

Thus, the correct answer is A. 0 N.

Would you like more details or have any other questions? Here are some related questions to consider:

1. What happens to the motion of the box if the forces are unbalanced?
2. How would friction impact this situation?
3. Can you explain how Newton's first law applies to this scenario?
4. What would happen if the force to the right was increased by 10 N?
5. How does this situation relate to equilibrium?

Tip: When forces on an object are balanced (equal in magnitude and opposite in direction), the object remains stationary or continues moving at a constant velocity.