Question

If Rohit moves along a circular path from point $A(0,0)$ as shown in the figure and reaches diametrically opposite point $B(5,0)$, what is his displacement vector? Given: radius of circle is $2.5$ unit.

• A. $0$
• B. $5\hat{i}+5\hat{j}$
• C. $5\hat{j}$
• D. $5\hat{i}$

Answer 1

The correct option is D $5\hat{i}$

The displacement vector is the difference between the position vector of the final point ($B$ here) and the initial point ($A$ here).
So, $\overrightarrow{r_B}=(5\hat{i}+0\hat{j})$ and $\overrightarrow{r_A}=(0\hat{i}+0\hat{j})$
Hence, displacement is given by
$\overrightarrow{S}=\overrightarrow{r_B}-\overrightarrow{r_A}=(5\hat{i}+0\hat{j})-(0\hat{i}+0\hat{j})=5\hat{i}$