Question

Seeta is moving due East with a velocity of $1\text{m/s}$ and Geeta is moving due West with a velocity of $2\text{m/s}$. What is the velocity of Seeta with respect to Geeta?

• A. $1\text{m/s}$ due east
• B. $1\text{m/s}$ due west
• C. $3\text{m/s}$ due east
• D. $3\text{m/s}$ due west

Answer 1

The correct option is C $3\text{m/s}$ due east

This is a one dimensional motion since it is only along the east-west direction. So, let us choose the east direction as positive and the west as negative. Now, given that
$\overrightarrow{v_S}$= Velocity of Seeta $=1\hat{i}\text{m/s}$
And $\overrightarrow{v_G}=$ Velocity of Geeta $=-2\hat{i}\text{m/s}$
Thus, $\overrightarrow{v_{SG}}=$ Velocity of Seeta with respect to Geeta
$\overrightarrow{v_{SG}}={\overrightarrow{v}}_S-{\overrightarrow{v}}_G=1\hat{i}-(-2)\hat{i}=3\hat{i}\text{m/s}$