Question

A plane mirror is placed at origin parallel to y-axis, facing the positive x-axis. An object starts from (2m, 0, 0 ) with a velocity of $(2\hat{i}+2\hat{j})$ m/s. The relative velocity of image with respect to object is along

• A. Positive x - axis
• B. Negative x - axis
• C. Positive y - axis
• D. Negative y - axis

Answer 1

The correct option is B Negative x - axis

Given,

The velocity of the object is $v_o=2\hat{i}+2\hat{j}$

As the given mirror is plane, the velocity of the image will be the same but in opposite direction hence, the velocity of the image is $v_i=-2\hat{i}+2\hat{j}$

The relative velocity of the image with respect to the object can be given as the difference between the Velocity of the image and the velocity of the object.

Therefore,

$v_{io}=v_i-v_o$

$v_{io}=-2\hat{i}+2\hat{j}-\left(2\hat{i}+2\hat{j}\right)$

$v_{io}=-4\hat{i}$

Hence, the relative velocity of image with respect to object will be along the negative X-axis .