Answer:
-11.11 cm
Explanation:
The lens formula is defined as,
[tex]\frac{1}{f}= \frac{1}{v}-\frac{1}{u}[/tex]
Here, f is the focal length, u is the distance of an object, v is the distance of image.
Given that, the diverging lens is given so according to sign convention of diverging less, u and f should be negative.
Given that, distance of an cell phone in front of a diverging lens is [tex]u=-25 cm[/tex]
And its focal length is [tex]f=-20 cm[/tex].
Put the variables in lens formula. Therefore,
[tex]\frac{1}{-20}= \frac{1}{v}-\frac{1}{-25}\\ \frac{1}{v}=\frac{1}{-20}-\frac{1}{25}\\ \frac{1}{v}=-(\frac{5+4}{100}) \\v=-\frac{100}{9} \\ v=-11.11 cm[/tex]
Therefore the image is formed of this phone at a distance of -11.11 cm from the lens.
