Explanation:
It is given that,
Object distance from the mirror, u = -30 cm
Focal length of the mirror, f = +15 cm
Size of the object, h = 7.5 cm
We need to find the image distance and the size of the image.
Mirror's formula, [tex]\dfrac{1}{v}+\dfrac{1}{u}=\dfrac{1}{f}[/tex]
v is image distance
[tex]\dfrac{1}{v}=\dfrac{1}{f}-\dfrac{1}{u}\\\\\dfrac{1}{v}=\dfrac{1}{(15)}-\dfrac{1}{(-30)}\\\\v=10\ cm[/tex]
Let h' is the size of the image. So,
[tex]\dfrac{h'}{h}=\dfrac{-v}{u}\\\\h'=\dfrac{-vh}{u}\\\\h'=\dfrac{-10\times 7.5}{-30}\\\\h'=2.5\ cm[/tex]
So, the image is located at a distance of 10 cm and the size of the image is 2.5 cm.
