Question

"LENSES"

Show your solution.

1. What is the image distance and image size if a 5 cm tall object is placed a distance of 45.5 cm from a convex lens 

having a focal length of 15.4 cm?

2. What is the image distance and image size if a 3 cm object is placed a distance of 30.5 cm from a diverging lens 

having a focal length of -10.2 cm?

Answer 1

1)

$$\frac{1}{15.4}=\frac{1}{45.5}+\frac{1}{d_i}\\d_i=23.3\ cm\\h=-\frac{23.3}{45.5}5=-2.56\ cm$$

2)

$$\frac{1}{-10.2}=\frac{1}{30.5}+\frac{1}{d_i}\\d_i=-7.64\ cm\\h=-\frac{-7.64}{30.5}3=0.75\ cm$$