Question

For the vectors $\overset{\rightarrow}{a}$ and $\overset{\rightarrow}{b}$ shown in figure,$\overset{\rightarrow}{a}$ = $\sqrt { 3 }$ $\widehat{i}$+ $\widehat{j}$ and |$\overset{\rightarrow}{b}$| = 10 units while q = 23º, then the value of R = | $\overset{\rightarrow}{a}$ + $\overset{\rightarrow}{b}$ | is nearly –

• A. 12
• B. 13
• C. 14
• D. 15

Answer 1

Answer: (A)

12

Answer 2

tan b = $\frac{1}{\sqrt{3}}$

b = 30º

\ a = q + b = 53º

\ $\overset{\rightarrow}{b}$ = 10 cos 53$\widehat{i}$+ 10 sin 53$\widehat{j}$ = 6$\widehat{i}$+ 8$\widehat{j}$

\$\overset{\rightarrow}{a}$ + $\overset{\rightarrow}{b}$ = (6 +$\sqrt{3}$)$\widehat{i}$+ 9$\widehat{j}$