Question

an object of height 1.2m is placed before concave mirror of focal length 20cm so real image is formed at distance of 60cm from it .Find position of object . What will be height of image formed??​

Answer 1

Answer:

Given,

height of object= - 1.2m(By sign convention)

focal length= -20cm(By sign convention)

Image distance= -60cm(By sign convention)

To find,

1)Position of object=?

2)Height of the image formed=?

Solution,

Now by using mirror formula,

1/f = 1/v +1/u

1/u= 1/f-1/v

1/u= (1/-20) - (1/-60)

1/u= 3-1/-60

1/u=2/-60

u=-30

Now by Using Mirror formula. i. e- m= height of image / height of object = v/u

height of image/-1.2= - 60/-30

height of image = - 1.2*2m

= 2.4m

Hope you understand my answer and brainliest it

Answer 2

Answer:

u = 30 cm

$\display \text{h _i = 2.4 cm}$

Explanation:

We have given :

Focal length = 20 cm

Image distance =  60 cm

We have to find object distance .

We know :

1 / f = 1 / v + 1 / u

Since image formed is real :

f = - 20 cm and v = - 60 cm

1 / u = 1 - 3 / 60

u = - 30 cm

Hence object distance is 30 cm .

Also given object height = 1.2 cm

We know :

h_i / h_o = - v / u

h_i / 1.2 = - 60 / 20

h_i = - 2.4 cm

Hence image height is 2.4 cm .