Question

A small candle is 38 cm from a concave mirror having a radius of curvature of 24 cm. (a) what is the focal length of the mirror? (

Answer 1

For a concave mirror, the radius of curvature is twice the focal length of the mirror:

`r=2f`
where f, for a concave mirror, is taken to be positive.

Re-arranging the formula we get:

`f= (r)/(2)`
and since the radius of curvature of the mirror in the problem is 24 cm, the focal length is

`f= (24 cm)/(2) = 12 cm`