Final answer:
The net force on the object is found by subtracting the eastward force from the westward force, resulting in a net force of 18N directed west.
Step-by-step explanation:
When considering the net force on an object, we must take into account both the magnitudes and directions of the forces involved. In this case, we have a force of 30N directed west and another force of 12N directed east. To find the net force, we subtract the smaller force from the larger one, keeping in mind that these forces are in opposite directions, which makes this a one-dimensional problem.
Subtracting 12N (east) from 30N (west), we get a net force of 18N directed west. There's no need to use the Pythagorean theorem here since the forces are aligned along the same line (east-west axis). The Pythagorean theorem is only necessary when dealing with forces at angles to one another, as in examples that have northward and westward components.
Therefore, the net force on the object is 18N directed west.