Question

The resultant of two vectors acting at an angle of ${150}^{\circ }$ is of magnitude $10$ units and is perpendicular to one of the vectors. The magnitude of the other vector is :

• A. $\frac{20}{\sqrt{3}}N$
• B. $10\sqrt{3}N$
• C. $20N$
• D. $20\sqrt{3}N$

Answer 1

Answer: (C)

$20N$

Let $\overrightarrow{A}\&\overrightarrow{B}$ be the two vector and $\overrightarrow{R}$ be their resultant
Along vertical direction only resultant and vertical component of $\overrightarrow{B}$ are present.
So, $R=B\sin {150}^{o}orB=10\times 2=20$