Question

A man goes $10\text{m}$ towards North, then $20\text{m}$ towards east. Then, total length of displacement is

• A. $22.4\text{m}$
• B. $25\text{m}$
• C. $25.5\text{m}$
• D. $30\text{m}$

Answer 1

The correct option is A $22.4\text{m}$

Let x-axis and y-axis representing east and north directions respectively.
Let $\overrightarrow{r}$ represents the position vector of man from the origin.
$\Rightarrow \overrightarrow{r}=20\hat{i}+10\hat{j}$
$\therefore$ Displacement of man = $\left|\overrightarrow{r}\right|=\sqrt{{20}^2+{10}^2}\approx 22.4\text{m}$