Explanation:
Given that,
Object distance, u = -40 cm (negative for concave mirror)
The radius of curvature of the mirror, R = 64 cm
Radius of curvature = 2(Focal length)
f = -32 cm (negative for concave mirror)
Using mirror's formula,
[tex]\dfrac{1}{v}+\dfrac{1}{u}=\dfrac{1}{f}\\\\\dfrac{1}{v}=\dfrac{1}{f}-\dfrac{1}{u}\\\\\dfrac{1}{v}=\dfrac{1}{(-32)}-\dfrac{1}{(-40)}\\\\v=-160\ cm[/tex]
So, the image will form at a distance of 160 cm from the mirror.
