Question

$|\overrightarrow{A}|=4units$

$|\overrightarrow{B}|=10units$ If angle between $\overrightarrow{A}$ & $\overrightarrow{B}$ is ${60}^{\circ }$ then find $\overrightarrow{A}$ . $\overrightarrow{B}$.

• A. $20$
• B. $40$
• C. $0$
• D. $20\sqrt{3}$

Answer 1

The correct option is A

$20$

$\overrightarrow{A}$.$\overrightarrow{B}$ = $|A||B|cos{60}^{\circ }$ .

$|\overline{A}|=4$ ; $|\overline{B}|=10$

= $4\times 10\times \frac{1}{2}$

Scalar product of $\overrightarrow{A}$ & $\overrightarrow{B}$ = 20