Question

A security mirror used in a big showroom has radius of curvature 5 m. If a customer is standing at a distance of 20 m from the cash counter, find the position, nature and size of the image formed in the security mirror.

Answer 1

Given, R = 5 m, f = `5/2`, u = –20 m and v = ?

Hence, on applying the values,

`2/R=1/v+1/u`

`2/5=1/v-1/20`

`1/v=2/5+1/20`

`1/v=(8+1)/20`

`1/v=9/20`

v = `20/9`

v = 2.8 m

Nature of the image: Erect, virtual, small and diminished.