An object is 12 cm in front of a concave spherical mirror,and the image is 3.0 cm in front of the mirror.What is the focal length of the mirror?
A)0.25 cm
B)15 cm
C)4.0 cm
D)2.4 cm
E)1.3 cm

Question

Quizplus · Accepted Answer

The image is virtual and upright, so the mirror is concave. The magnification is -1, so the object and image are the same size. The object distance is 12 cm and the image distance is 3 cm, so the focal length is 4 cm.

An Object Is 12 Cm in Front of a Concave