Resultant vectors

Vectors in two dimensions combine to a single resultant that has the same effect as all of them together.

• Add vectors head-to-tail; the resultant runs from the first tail to the last head.
• For perpendicular vectors, use Pythagoras for magnitude and tan θ for direction.
• The equilibrant is equal in magnitude but opposite in direction to the resultant.
• Always state the direction of a resultant, measured from a stated reference.

• Resultant — the single vector equal to the sum.
• Equilibrant — the vector that balances the resultant.