Question

If $|\overrightarrow{A}+\overrightarrow{B}|=|\overrightarrow{A}|+|vecB$, then angle between $\overrightarrow{A}$ and $\overrightarrow{B}$ will be

• A. ${90}^{\circ }$
• B. ${120}^{\circ }$
  
• C. $0^{\circ }$
  
• D. ${60}^{\circ }$

Answer 1

The correct option is C $0^{\circ }$


Resultant of two vectors $\overrightarrow{A}$ and $\overrightarrow{B}$ can be given by $\overrightarrow{R}=\overrightarrow{A}+\overrightarrow{B}$
$|\overrightarrow{R}|=|\overrightarrow{A}+\overrightarrow{B}|=\sqrt{A^2+B^2+2ABcos\theta }$
If $\theta =0^{\circ }then|\overrightarrow{R}|=A+B=|\overrightarrow{A}|+|\overrightarrow{B}|$