Question

Determine the image distance for a 10.00-cm tall object placed 30.5 cm from a convex lens having a focal length of 16.0 cm.

Answer 1

Given:

$d_o=30.5\:\rm cm$

$f=16.0\:\rm cm$

The equation of convex lens says

$$\frac{1}{d_o}+\frac{1}{d_i}=\frac{1}{f}$$

Hence, the image position

$$d_i=\frac{d_o f}{d_o-f}=\frac{30.5*16.0}{30.5-16.0}=33.7\:\rm cm$$