Question

A concave mirror forms a real image at 15.0 cm from the mirror surface along the principal axis. If the corresponding object is at a distance of 30.0 cm, what is the mirror's focal length? Please show your work

Answer 1

Focal length, f = 10 cm

Step-by-step explanation:

We have,

A concave mirror forms a real image at 15.0 cm from the mirror surface along the principal axis, it means that the image distance is 15 cm

The object is placed at a distance of 30 cm, u = -30 cm

It is required to find the focal length of the mirror. Let it is f. Using mirror's formula to find it:

`(1)/(v)-(1)/(u)=(1)/(f)\\\\(1)/(15)-(1)/((-30))=(1)/(f)\\\\f=10\ cm`

So, the focal length of the mirror is 10 cm.