Final answer:
The net force acting on an object can be found by considering the direction and magnitude of the individual forces. For option (d) with forces of 64 N [N] and 38 N [W], the net force is approximately 74.43 N.
Step-by-step explanation:
The net force acting on an object depends on the combination of forces acting on it. In this case, we are given four forces: 126 N [E], 126 N [W], 18 N [W], and 18 N [E]. To find the net force, we need to consider the direction and magnitude of the forces.
For option (d), a free-body diagram would show a northward force of 64 N and a westward force of 38 N. The net force is equal to the sum of the two applied forces. Using the Pythagorean theorem, we can find the magnitude of the net force:
net force = √(64^2 + 38^2) = √(4096 + 1444) = √5540 ≈ 74.43 N