Question

Object O is moving with velocity $\hat{i}+2\hat{j}+3\hat{k}$ and mirror (lies in y-z plane) is moving with velocity $2\hat{i}$

• A. Velocity of image w.r.t ground $3\hat{i}+2\hat{j}+3\hat{k}$
• B. Velocity of image w.r.t mirror $\hat{i}+2\hat{j}+3\hat{k}$
• C. Velocity of image w.r.t object $2\hat{i}$
• D. Velocity of image w.r.t mirror $-\hat{i}+2\hat{j}+3\hat{k}$

Answer 1

Answer: (D)

Velocity of image w.r.t mirror $-\hat{i}+2\hat{j}+3\hat{k}$

Given,

The velocity of the moving object $v_u=\hat{i}+2\hat{j}+3\hat{k}$

The velocity of moving mirror $v_m=2\hat{i}$

Hence the velocity of image with respect to mirror is

$v_{im}=v_u-v_m\Rightarrow v_{im}=\hat{i}+2\hat{j}+3\hat{k}-2\hat{i}$

$\therefore v_{im}=-\hat{i}+2\hat{j}+3\hat{k}$