Question

A point object is 10 cm away from a plane mirror, and the eye of an observer

(with pupil diameter 5.0 mm ) is 20 cm away. Assuming the eye and the object

to be on the same line perpendicular to the mirror surface, find the area of the

mirror used in observing the reflection of the point.

Short answer

The area of the mirror used in observing the reflection of the point is$2.2m{m}^2$.

Step-by-step solution

The given data

a) Object distance, $p=10\mathrm{cm}$

b) Distance of observer,localid="1663050290588" width="82">dey=20cm

c) Diameter of the pupil,localid="1663050421329" $D=5mm$

Understanding the concept of the geometry

The area of the mirror can be determined by using the object's distance.

Formula:

The area of the circle, $A=\frac{{\mathrm{\pi d}}^2}{4},d=diameterofcircle$ (i)