What is the least number of unequal non-zero vectors that can be added to give a resultant equal to zero?
A) 2
B) 3
C) 4
D) 5
E) It cannot be done.

Question

Quizplus · Accepted Answer

The minimum number of unequal non-zero vectors that can be added to give a resultant of zero is three. This is because in two dimensions, two non-parallel vectors can only form a triangle, which cannot have a zero resultant. In three dimensions, two non-parallel vectors can form a parallelogram, which also cannot have a zero resultant. Three non-coplanar vectors, however, can form a closed triangular pyramid, with the tip at the origin, and thus have a zero resultant.

What Is the Least Number of Unequal Non-Zero Vectors That