You use a camera with a lens of focal length 50.0 mm to take a picture of a 2.50 m tall statue located 7.20 m away. If the image height on the film is 18.2 mm, what is the distance from the lens to the film?
A) 5.04 cm
B) need more information
C) 6.32 mm
D) 5.24 cm

Question

Quizplus · Accepted Answer

Using the thin lens equation: 1/f = 1/o + 1/i, where f is the focal length, o is the object distance, and i is the image distance.

We can solve for the image distance:
1/50 = 1/720 + 1/i
1/i = 1/50 - 1/720
i = 5.24 cm

Therefore, the distance from the lens to the film is 5.24 cm.

You Use a Camera with a Lens of Focal Length