Question

2) An object is placed at the
distance 4 cm in front of
mirror . whose focal
length is, 5.cm- where is the image formed?​

Answer 1

Answer:

20cm

Explanation:

u=4

v=?

f=5

1/f=1/u+1/v

1/5=1/4+1/v

1/5-1/4=1/v

4-5/20=1/v

v= 20

Answer 2

Answer:2.22cm

Explanation:

Firstly the mirror is convex mirror because its focal length is +5cm which mean that focal length is in direction of incident light .

distance of object from mirror , u = -4cm ( Opposite to the direction of indcident light )

Focal length of the mirror , f = 5cm

Distance of image from mirror , v = ?

1/f = 1/v + 1/u

1/5 = 1/v + 1/-4

1/5 = 1/v - 1/4

1/5 + 1/4 = 1/v

9/20 = 1/v

v = 20/9

v = 2.22 cm

Henceforth,the value of Distance of image from the mirror is 2.22 cm