Final answer:
The resultant of two forces is a single force that has the same effect as the original forces combined. It is calculated by adding the magnitudes algebraically if the forces act along the same line, or by vector addition for forces with different directions.
Step-by-step explanation:
The term resultant of two forces refers to the single force that represents the combined effect of these two forces. When forces are acting in the same direction, their magnitudes simply add up to form the resultant force. However, if the forces act in opposite directions, one force is considered positive and the other negative, depending on the chosen direction as positive. To find the resultant vector, which is the vector sum of the two forces, we apply vector addition.
For example, if two skaters are pushing a third from different directions, the resulting acceleration of the third skater would be due to the net external force, which is the vector sum of all the forces. Mathematically, if two forces are acting along the same line, the resultant force is calculated by algebraically adding the magnitudes; if the forces are represented as vectors in different directions, the resultant vector is found by geometric or algebraic vector addition, considering both magnitude and direction.