JAMB Physics 2021 Paper

Concept:For a plane mirror, the image is formed at the same distance behind the mirror as the object is in front of it.Explanation:The man is initially $4 \, \text{m}$ in front of the mirror.When the mirror is moved $1 \, \text{m}$ towards him, the new distance between the man and the mirror becomes:$$4 \, \text{m} - 1 \, \text{m} = 3 \, \text{m}$$For a plane mirror, object distance equals image distance.So the image is now formed $3 \, \text{m}$ behind the mirror.The total distance between the man and his new image is therefore:$$\text{distance} = 3 \, \text{m} + 3 \, \text{m} = 6 \, \text{m}$$Thus, the correct option is C.Answer:C. $6 \, \text{m}$