Question

An object is moving towards a stationary plane mirror with a speed of $2m/s$ in left. Velocity of the image w.r.t. the object is

• A. $2m/s$ towards right
• B. $4m/s$ towards right
• C. $2m/s$ towards left
• D. $4m/s$ towards left

Answer 1

The correct option is D $4m/s$ towards left

$\begin{array}{c}O=\text{Object}\\ i=\mathrm{image}\\ \text{As the object is approaching}\\ \text{mirror with}2{ms}^{-1}\text{, then the}\\ \text{image will also approach the}\\ \text{mirror with same speed.}\end{array}$

$\begin{array}{cc}& v_0\text{, speed of object}=-2{ms}^{-1}\left(\mathrm{right}\right)\\ & v_i\text{, speed of image}=-2{ms}^{-1}\left(\mathrm{right}\right)\\ & \begin{array}{cc}\text{speed of image with respect to}& \\ \text{object}=V_i-V_0& =2-(-2)\\ & =4{ms}^{-1}\left(right\right)\end{array}\end{array}$