Explanation

(a) [image:9_image69.emf]
According to New Cartesian sign convention,
Object distance $u = - 15\ cm$
Focal length of a concave lens, $f = - 10\ cm$
Height of the object $h_{o} = 2.0\ cm$
According to mirror formula, $\frac{1}{v} + \frac{1}{u} = \frac{1}{f}$
$\frac{1}{v} = \frac{1}{f} - \frac{1}{u} = \frac{1}{- 10} - \frac{1}{- 15} \Rightarrow v = - 30\ cm$
This image is formed 30 cm from the mirror on the same side of the object. It is a real image
Magnification of the mirror, $m = \frac{- v}{u} = \frac{h_{I}}{h_{O}}$
$\Rightarrow \frac{- ( - 30)}{- 15} = \frac{h_{I}}{2}\ \Rightarrow h_{I} = - 4\ cm$
Negative sign shows that image is inverted
The image is real, inverted, of size 4 cm at a distance 30 cm in front of the mirror