Two vectors of same magnitude have a resultant equal to either of the two vectos. The angle between two…
Two vectors of same magnitude have a resultant equal to either of the two vectos. The angle between two vectors is
$\operatorname{cos}^{-1}(-0 \cdot 3)$
$\cos ^{-1}(-0-6)$
$\operatorname{cos}^{-1}(-0 \cdot 4)$
$\operatorname{cos}^{-1}(-0 \cdot 5)$
Solution
This is an important result to remember. Two vectors at 120 degree produce a vector equal to their magnitude. Let their magnitude be a,
$\begin{array}{l}
\text { Resultant }=a=\sqrt{\left(a^{2}+a^{2}+2 \times a \times a \times \cos \theta\right)}=a \sqrt{(2+2 \cos \theta)} \Rightarrow \cos \theta=-\frac{1}{2} \\
\Rightarrow \theta=120^{0}
\end{array}$