A concave mirror of radius of curvature 40 cm forms a real image twice as large as the object.
the object distance is

Habeeb Horlalekan

12 years ago

Focal length =r/2 =40/2=20cm :but m=v/u=2:v=2u:: 1/f=1/2u 1/u

1/20=1/2u 1/u

1/20=2 1/u

3*20=u =60cm but we have 2u =v :

2u =60cm:

u =30cm

2u

KindnessIdeal

2 years ago

F=UV/U+V
F=r/2
F=40/2 =20cm
20= Ux2U/2U +U
20= Ux2U/3U
20= 2U/ 3
60= 2U
U= 30cm

amaechi unya

13 years ago

Ok dats correct twice de image de distance is̶̲̥̅̊ 30cm