Two vectors of magnitude 10 each have an angle 120° between them. A third vector of magnitude 10√3 acts exactly opposite to the resultant of the first two. Find the final resultant magnitude.
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Question

Two vectors of magnitude 10 each have an angle 120° between them. A third vector of magnitude 10√3 acts exactly opposite to the resultant of the first two. Find the final resultant magnitude.

G1 Physics · Accepted Answer

The resultant of the first two equal vectors at 120° is 10. The third vector 10√3 is opposite to it, so final magnitude=10√3−10=10(√3−1).