An object is 1.0 m in front of a mirror.A virtual image is formed 10.0 m behind the mirror.What is the radius of curvature of the mirror?
A)0.56 m
B)1.1 m
C)2.2 m
D)4.4 m
E)This problem cannot be solved without more information.

Question

Quizplus · Accepted Answer

Using the mirror formula,

1/f = 1/di + 1/do

where f is the focal length (or twice the radius of curvature), di is the image distance (negative for virtual images), and do is the object distance.

Plugging in the given values,

1/f = 1/-10 + 1/1

1/f = -1/10 + 10/10

1/f = 9/10

f = 10/9 m

So, the radius of curvature is twice the focal length,

R = 2f = 20/9 m ≈ 2.2 m (Option C).

An Object Is 1