Question

please tell me the answer. I will mark them as brainiest if answered please
A small insect is at 60 cm from a concave mirror of focal length 20 cm. What is the image distance from the mirror?
30 cm

20 cm

15 cm

18 cm

Answer 1

Answer:

given

focal length(F) = 20cm

Image distance(v)= 60cm

mirror formula

  1/20=1/60+1/u

1/20-1/60=1/u

Lcm=60

=3-1/60=2/60= 1/30

your answers is 30cm

hope it had helped you

Answer 2

Answer:

The image distance from the mirror will be = 30cm

Explanation:

Now by using the mirror formula,

1/u + 1/v = 1/f

Here, we have, u = +60cm

and, f= +20 ( which is real and positive convention)

Now putting the values in mirror formula we get,

1/v + 1/60 = 1/20

implies,

1/v = 1/20 - 1/60 = 3/60 - 1/60 = 2/60 = 1/30

Therefore, v= 30cm

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