A side-view convex mirror of an automobile has a radius of curvature of 3 m. If the bus is located 5 m from this mirror. Find the ratio of the size of the image to the size of the object.

Object distance u = -5 m

The radius of curvature = 3 m, therefore

Focal length f = 1.5 m

Substituting values in the equation,

$\frac{1}{\mathrm{f}} = \frac{1}{\mathrm{v}}+\frac{1}{\mathrm{u}}$

$\frac{1}{1.5} = \frac{1}{\mathrm{v}}+\frac{1}{-5}$

$\frac{1}{\mathrm{v}}=\frac{1}{1.5}+\frac{1}{5}$

$\frac{1}{\mathrm{v}}=\frac{5+1.5}{7.5}$

$\mathrm{v}=\frac{7.5}{6.5}=\frac{15}{13}$m

m = $-\frac{\mathrm{v}}{\mathrm{u}}$

= $-\frac{\left({\displaystyle \frac{15}{13}}\right)}{-5}$ 

= $\frac{3}{13}$

= 0.23