Question

An object 5 cm high is held 25 cm away from a converging lens of focal length 10 cm.

What is image distance?

Answer 1

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

$\frac{1}{10}=\frac{1}{v}-\frac{1}{-25}$

$\frac{1}{v}=\frac{1}{10}-\frac{1}{25}$

$\frac{1}{v}=\frac{5-2}{50}v=\frac{50}{3}=16.67cm$