Mirrors and Lens

Question

A 2.00-cm-tall object is 18.0 cm in front of a converging lens with a focal length of 34.0 cm.

Calculate the image distance (dI) and image height (hI). Follow the sign convention

Answer 1

Using 1/di + 1/d0 = 1/f we fet 1/di = 1/34 - 1/18

di = -38.25 cms

The image is therefore virtual and upright

The magnification is -di/do = 38.25/18 = 2.125

The image size is therefore 2.125 x 2 cms = 4.25 cms