Concept:Vector addition and the conditions for a zero resultant vector.
Formula:$$\vec{R} = \vec{A} + \vec{B} + \vec{C} = 0$$
Solution:- A single non-zero vector can never have a zero resultant because there is no other force to cancel its magnitude.
- Two vectors can only yield a zero resultant if they have equal magnitudes and point in exactly opposite directions. If they are of unequal magnitude, they cannot cancel each other out.
- Three coplanar vectors of unequal magnitude can be arranged such that they form a closed triangle when joined head-to-tail, which makes their vector sum exactly zero.
Why other options are incorrect:- A is incorrect because two unequal vectors will always leave a non-zero net force in the direction of the larger vector.
- C and D are incorrect because while 4 or 5 unequal vectors can sum to zero, they do not represent the minimum number required.
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