Question

A 24.8 cm tall object is placed in
front of a lens, which creates a
-3.09 cm tall image. If the object is
37.5 cm from the lens, what is the
image distance?

Answer 1

Answer:

Image distance, v = 4.67 cm

Explanation:

We have,

Height of the object, h = 24.8 cm

Height of the formed image, h' = -3.09 cm

Object distance, u - -37.5 cm

It is required to find the image distance. Lens formula is :

$\dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}$

Using formula of magnification,

$m=\dfrac{v}{u}=\dfrac{h'}{h}$

v is image distance

$v=\dfrac{uh'}{h}\\\\v=\dfrac{-37.5\times (-3.09)}{24.8}\\\\v=4.67\ cm$

So, the image distance is 4.67 cm.