Question

an object 5 cm in height is placed at a distance of 30 M in front of a concave mirror of focal length 40 cm by scale drawing find the nature size position and magnification of the image

Answer 1

Size of object = 5 cm 

Object distance = - 30 m = -3000 cm = u 

Focal length = - 40 cm = f 

Mirror equation : 

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

$\frac{1}{-40}= \frac{1}{v} + \frac{1}{-3000}$

$\frac{1}{v}= \frac{1}{3000} - \frac{1}{40}$

$\frac{1}{v} = \frac{40 - 3000}{120000}$

$\frac{1}{v} = \frac{-2960}{120000}$

v = - 40.54 cm 

m = -v/u 

m = 40.54 /- 3000

m = -0.0135 

the image is highly diminished it is real and inverted