Question

Projection of $\overrightarrow{A}=\hat{i}-\hat{j}+2\hat{k}$ along $\overrightarrow{B}=-\hat{k}$ is

• A. $0$
• B. $2$
• C. $-2$
• D. $1$

Answer 1

The correct option is C $-2$

We know that the projection of $\overrightarrow{A}$ along $\overrightarrow{B}$ is given as
$\frac{\overrightarrow{A}\cdot \overrightarrow{B}}{|\overrightarrow{B}|}$
$\Rightarrow \frac{(\hat{i}-\hat{j}+2\hat{k}).(-\hat{k})}{\sqrt{1^2}}=-2$