Question

An object is placed at a distance of 20 cm from a convex mirror of a focal length of 15 cm. Find the position and nature of the image.

Answer 1

Step 1, Given data

Object distance u = -20 cm

Focal length f = +15

Let image distance be v

Step 2, Finding the image distance

From the mirror formula, we know

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

Putting all the values

$\frac{1}{v}-\frac{1}{20}=\frac{1}{15}$

After solving

v = 8.57 cm

Hence the image is formed at 8.57 cm and its nature is virtual, erect, and diminished.