A concave mirror with focal length 17.0 cm is placed 38.0 cm to the left of the object.A convex lens of focal length 18.0 cm is placed 54.0 cm to the right of the object.Where is the image formed by both the mirror and the lens?

Question

Quizplus · Accepted Answer

Using the mirror formula, we have:
1/f = 1/do + 1/di
1/17 = 1/38 + 1/di
di = 25.86 cm (image distance from the mirror)
Using the lens formula, we have:
1/f = 1/di' + 1/do'
1/18 = 1/di' + 1/54
di' = 25.5 cm (image distance from the lens)
The final image distance is the distance between the mirror and the lens:
di_total = di - d_mirror_to_lens - di'
di_total = 25.86 - 16.0 - 25.5
di_total = 13.36 cm
Therefore, the image is formed 13.36 cm to the right of the object, which is choice B.

A Concave Mirror with Focal Length 17