Question

If $|\overline{A}+\overline{B}|=|\overline{A}|+|\overline{B}|$ then the angle between $\overline{A}$ and $\overline{B}$ is:

• A. 0${}^0$
• B. 90${}^0$
• C. 180${}^0$
• D. 60${}^0$

Answer 1

Answer: (A)

0${}^0$

$|\overrightarrow{A}+\overrightarrow{B}|=|\overrightarrow{A}|+|\overrightarrow{B}|$
squaring both the sides
$A^2+B^2+2ABcos\theta =A^2+B^2+2AB$
$cos\theta =+1$
$\theta =0^o$