Question

Given that $0.2\hat{i}+0.6\hat{j}+a\hat{k}$ is a unit vector. What is the value of a?

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

Here $(0.2{)}^2+(0.6{)}^2+a^2=1$ or $a^2=1-0.04-0.36,=0.6$ or $a=\sqrt{0.6}.$ So the correct choice is (c).