Question

when an object placed at the distance of 15 cm from a concave mirror its image is formed at 10 cm in front of the image calculate the of the mirror​

Answer 1

u = -15

v = 10

Now,

1/f = 1/v + 1/u

1/f = 1/10 - 1/15

1/f = (3 - 2)/30

1/f = 1/30

therefore,

f = 30cm