Question

A person is standing in front of a plane mirror at a distance of 6 m from it. The mirror is displaced 1 m away from the person. The person then moves 2 m towards his right and then 1.5 m towards the mirror.
What will be the distance between the person and his image now?

• A. 5.5 m
• B. 8.5 m
• C. 11 m
• D. 17 m

Answer 1

The correct option is C 11 m

Initially the person is standing at a distance of 6 metres from the mirror as shown.
Then, the mirror is displaced 1 m away from the person, therefore, the distance between person and mirror becomes 7 m.
Further, the person moves 1 m towards his right(from A to B) and then 1.5 m towards the mirror (from B to C) as shown.
Here, the person moved 1.5 m towards the mirror. Therefore, the final distance of the person from the mirror becomes 7-1.5= 5.5 m. So, the distance of the image from the mirror will also be equal to 5.5 m.
In the question, we were asked to calculate the distance between the person and his image.
Hence, it will be 5.5+5.5=11 m.