Question

2. A lens is being used to look at an object 40cm away. An image appears 20 points

30 cm away. What is the focal length of the lens?

Answer 1

f = 17.14 cm

Step-by-step explanation:

Given that,

The object distance, u = -40 cm

The image distance, v = +30 cm

We need to find the focal length of the lens. The lens formula is given by :

`(1)/(v)-(1)/(u)=(1)/(f)\\\\(1)/(f)=(1)/(30)-(1)/((-40))\\\\f=17.14\ cm`

So, the focal length of the lens is 17.14 cm.