Question

A convex mirror produces a magnification of 1/2 when an object is placed at a distance of 0.8m from it.Where should the object be placed so that the size of the image becomes 1/2 of the object?​

Answer 1

u=-60cm

m=1/2

m=-v/u

1/2=-v/-60

-v=-30cm

v=30cm

f=?

by mirror formula:

-1/60+1/30=1/f

on solving:

f=60cm

m=1/3

1/3=-v/u

v=(1/3)u

f=60cm

using mirror formula:

1/u+1/v=1/f

1/u-3/u=1/60

u=-120cm.