Thus we conclude that any two vectors which have the same magnitude and are parallel to each other are equal. If they are not parallel then they cannot be equal no matter what their magnitude.

In physical situations even two equal
vectors may produce different effects depending on
where they are located. For example take the force applied
on a disc. If applied on the rim it rotates the wheel
at a speed different from when it is applied to a
point nearer to the center. Thus although it is the
same force, applied at different points it produces
different effects. On the other hand, imagine a thin
rope wrapped on a wheel and being pulled out horizontally
from the top. On the rope no matter where the force
is applied, the effect is the same. Similarly we
may push the wheel by applying the same force at
thee end of a stick with same result (see figure
3).