Question

An object and a concave mirror are approaching each other with velocities $10 m/s$ and $5 m/s$ as shown in figure. The velocity of image of object at the instant shown in figure is

• A. $65 \,m/s\, \hat{i}$
• B. $65 \,m/s- \hat{i}$
• C. $40\, m/s\,\hat{i}$
• D. $40\, m/s- \hat{i}$

Answer 1

Answer: (B)

The formula for velocity of image is given by:
$=V_{I m}=\frac{f}{f-u}=\frac{-10}{-10+15}=-2$
$\therefore V _{ Im }=-4 V _{ Om }$
Therefore, $\vec{V}_{ I }-5-\hat{1}=-410 \hat{1}+5 \hat{1}$
$\Rightarrow \vec{V}_{I}=-65 \hat{\imath}$