Question

An object is placed at a distance of 25 cm from the pole of a spherical mirror which forms a real, inverted image on the same side of object at 31.5 cm from the pole. Calculate the focal length of mirror and find the nature of the mirror.

Answer 1

Given that,

Object distance,u=-25cm
Image distance=-31.5 cm
For a mirror,we know that,
1/f=1/v+1/u
=1/(-31.5) +1/(-25)
f=-13.93cm= -14 cm

This will be a concave mirror.