Question

an object of height 1.2 m is a placed before a concave mirror of focal length20 cm so that a real image is formed at a distance of 60 cm from it find the position of an object what will be the height of the image formed

Answer 1

Given: height of object = 1.2m
f = -20cm
v = -60cm
1/f = 1/v+1/u
1/-20 = 1/-60+1/u
1/u = -1/30
u = -30cm
-v/u = hi/ho
+60/-30 = hi/120
hi = -240cm

Answer 2

Given

Concave Mirror

Focal Length (f) = -20cm

Image Distance (v) = -60cm

Object Distance (u) = u

Mirror Formula => 1/f = 1/u + 1/v

=> 1/u = 1/f - 1/v

=> 1/u = 1/-20 - 1/-60

=> 1/u = 1/60 - 1/20

=> 1/u = (1 - 3)/60

=> 1/u = -2/60

=> u = -30cm