Question

A converging lens has a focal length of 0.36 m. If an object is placed at 0.21 m from the lens, where will its image be located?

Answer 1

`0.504\text{ }m\text{ in front of the lens}`

Step-by-step explanation

We want to determine the position where the image will be formed.

To do this, we apply the formula:

`(1)/(f)=(1)/(u)+(1)/(v)`

where f = focal length

u = distance of the object from the lens

v = distance of the image from the lens

Solving for v, we have the position that the image is formed:

`\begin{gathered} (1)/(0.36)=(1)/(0.21)+(1)/(v) \\ (1)/(0.36)=(v+0.21)/(0.21v) \\ 0.21v=0.36(v+0.21) \\ 0.21v=0.36v+0.0756 \\ 0.21v-0.36v=0.0756 \\ -0.15v=0.0756 \\ v=(0.0756)/(-0.15) \\ v=-0.504\text{ }m \end{gathered}`

Since this distance is negative, we say that the image formed is a virtual image and it is formed 0.504 m in front of the lens.