Question

Aconverging mirror forms a real image of height 4cm of an object of height 1cm placed 20cm away from the mirror. Calculate the image distance. What is the focal Length of the mirror?​

Answer 1

Answer:

height of image / height of object = -v/u

4/1 = -(-v)/-20

v = -80cm

the image distance is -80cm in front of mirror..

use mirror formula to find focal length..

1/f = 1/v + 1/u

1/f = 1/-80 - 1/20

1/f = (-1 -4)/80

1/f = -5/80

f = - 16cm

thus the focal Length of the mirror is -16cm