An object is placed 12 cm in front of a curved mirror. The magnification of the image is -3.0. What is the focal length of the mirror?
A)12 cm
B)9.0 cm
C)24 cm
D)36 cm
E)16 cm

Question

Quizplus · Accepted Answer

The magnification (m) is given by the formula m = - (image distance/object distance). Here, m = -3.0 and object distance = 12 cm. Solving for image distance gives 36 cm. Using the mirror formula (1/f = 1/object distance + 1/image distance), we find the focal length (f) to be 9.0 cm.

An Object Is Placed 12 Cm in Front of a Curved