Question

Suppose you place an object 8 cm in front of a converging lens and the image appears 16 cm on the other side of the lens. What is the focal length of the lens?

Answer 1

5.33 cm

Step-by-step explanation:

The lens equation states that:

`(1)/(f)=(1)/(p)+(1)/(q)`

where

f is the focal length

p is the distance of the object from the lens

q is the distance of the image from the lens

In this problem,

p = 8 cm

q = 16 cm ( the sign is positive since the image is real, which means it is formed on the other side of the lens)

Substituting into the equation,

`(1)/(f)=(1)/(8 cm)+(1)/(16 cm)=(3)/(16 cm)`

`f=(16)/(3)cm=5.33 cm`