Question

Find the value of $10b$ , if a unit vector is represented as $(0.8\hat{i}+b\hat{j}+\sqrt{0.2}\hat{k})$ .

Answer 1

Answer: 4

Unit vector $(0.8\hat{ı}+b\hat{ȷ}+\sqrt{0.2}\hat{k})$
$\therefore \sqrt{(0.8{)}^2+b^2+(\sqrt{0.2}{)}^2}=1$
$\therefore 0.64+b^2+0.2=1$
$\therefore b^2=1-0.84=0.16$
$\therefore b=0.4$