Question

Focal length of the concave mirror is 30cm object distance is 60cm. Find out the image

Answer 1

Answer :

Focal length = 30cm

Distance of object = 60cm

Type of mirror : concave

We have to find distance of image$.$

Focal length of concave mirror is taken negative.

We can solve this question simply by applying mirror formula.

Let's calculate ☃

➝ 1/u + 1/v = 1/f

➝ 1/(-60) + 1/v = 1/(-30)

➝ 1/v = -1/30 + 1/60

➝ 1/v = (-2 + 1) / 60

➝ v = -60/1

➝ v = -60cm

Answer 2

Given ,

Focal length (f) = -30 cm

Object distance (u) = 60 cm

We know that , the mirror formula is given by

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

Thus ,

-1/30 = 1/v + (-1/60)

1/v = -1/30 + 1/60

1/v = (-2 + 1)/60

v = -60/1

v = -60 cm

Note : the negative sign of v indicates the image is formed left of the mirror

$\therefore$The image distance is 60 cm