Answer to Question #122577 in Optics for Lisa

Question

3. Determine the image distance and image height for 5.0 cm tall object placed 45.0 cm
from a concave mirror having a focal length of 15.0 cm.

Answer 1

Given,

$f=-15cm,u=-45cm,h_0=5cm$

Now, we know that

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

Thus,

$$\frac{1}{-15}=\frac{1}{-45}+\frac{1}{v}$$

Hence,

$$v=-22.5cm$$

Since, $h_i/h_o=-v/u\implies h_i=-2.5cm$