Question

An object at a distance of 30 cm from a concave mirror gets its image at the same point. The focal length of the mirror is​

Answer 1

The focal length of the mirror is 15 cm

From the question given above, the following data were obtained:

Object distance (u) = 30 cm

Image distance (v) = 30 cm

Focal length (f) =?

The focal length of the mirror can be obtained as follow:

$\frac{1}{f} = \frac{1}{v} + \frac{1}{u} \\\\\frac{1}{f} = \frac{1}{30} + \frac{1}{30}\\\\\frac{1}{f} = \frac{2}{30} \\\\\frac{1}{f} = \frac{1}{15}$

Invert

f = 15 cm

Therefore, the focal length of the mirror is 15 cm

Learn more: brainly.com/question/1392083