Final answer:
The resultant vector is the vector sum of two or more vectors, and its effect is the same as the individual vectors combined.
Step-by-step explanation:
The resultant vector is the vector sum of two or more vectors. When combining vectors, each vector's magnitude and direction contribute to the overall effect. To find the resultant, often vectors are placed in a head-to-tail fashion and a new arrow is drawn from the tail of the first vector to the head of the last vector, which then represents the resultant. This resultant vector's effect is equivalent to all the combined vectors acting together.
For example, if we were to add vectors A and B that are parallel, the resultant magnitude is R = A + B, and its direction is in line with the original vectors. If vectors are antiparallel, their difference would be calculated to find the difference vector D.