Question

An object is placed 40 cm in front of a concave mirror of focal length 20 cm. A plane mirror is placed at a
distance of 10 cm in front of the concave mirror. Find the final position of the image.

Answer 1

Given :-

Position of object = u = -40 cm

Focal length = f = -20 cm

By Mirror Formula,

1/v + 1/u = 1/f

1/v = 1/f - 1/u

1/v = -1/20 + 1/40

1/v = -2+1/40

1/v = -1/40

v = -40 cm

Therefore,

Position of Image = v = -40 cm