Question

Magnitude of vector which comes on addition of two vectors, $6\widehat{i} + 7\widehat{j}$ and $3\widehat{i} + 4\widehat{j}$ is

• A. $\sqrt{136}$
• B. $\sqrt{13.2}$
• C. $\sqrt{202}$
• D. $\sqrt{160}$

Answer 1

Answer: (C)

$\sqrt{202}$

Answer 2

$\overrightarrow{R} = \overrightarrow{A} + \overrightarrow{B}$= $6\widehat{i} + 7\widehat{j} + 3\widehat{i} + 4\widehat{j}$= $9\widehat{i} + 11\widehat{j}$

∴ $|\overrightarrow{R}|\mspace{6mu} = \mspace{6mu}\sqrt{9^{2} + 11^{2}} = \sqrt{81 + 121} = \sqrt{202}$