A 2.0 cm high object is placed on the principal axis of a concave mirror at a distance of 12 cm from the pole. If the image is inverted, real and 5.0 cm high, find the location of the image the focal length of the mirror.

Explanation

The magnificatin is `m=v/u `
or `(-5.0cm)/(2.0cm)=(-v)/(-12cm)`
`or v-30cm`
The image is formed at 30 from the pole on the side of the object. We have
`1/f=1/v+1/u`
`=1/(-30cm)+1/(-12cm)=7/(60cm)`
`or f=-(60cm)/7=-8.6cn,