A stationary object is initially 2 m from a plane mirror. The mirror moves normally away from the object at 0.5 m/s for 4 s. By how many metres does the object-image separation increase?
Physics · Geometrical optics · law of reflection and plane mirror
JEE Mains NEET

Question

A stationary object is initially 2 m from a plane mirror. The mirror moves normally away from the object at 0.5 m/s for 4 s. By how many metres does the object-image separation increase?

G1 Physics · Accepted Answer

The mirror moves 2 m. With the object fixed, the image moves 4 m in the same direction, so the object-image separation increases by 4 m.