question_answer

An observer is standing at a point 0, at a distance of 100 cm from a convex lens of focal length\[50\text{ }cm\]. A plane mirror is placed behind the lens at a distance of \[150\text{ }cm\]from the lens. The mirror now starts moving towards the right with a velocity of\[10\text{ }cm/s\]. What will be the magnitude of velocity (in cm/s) other own image as seen by the observer, at the moment when the mirror just starts moving?

Answer:

2.22