The Focal Length of the Lens of a Simple Film

question 75

Multiple Choice

The focal length of the lens of a simple film camera is 40.0 mm.By what amount should the distance between the lens and the film be increased or decreased to change the focus from a person who is 25 m from the lens to one who is 4.0 m from the lens?

• A)0.2 mm
• B)0.3 mm
• C)0.4 mm
• D)0.5 mm
• E)0.7 mm