Question

A concave mirror produces a real image of height 2cm of an object of height 0.5cm place 10cm away from the mirror.Find the position of the image and focal length of the mirror?

Answer 1

h'=2cm
h=0.5cm
u=-10cm
v=

Answer 2

h = 0.5 cm

h’ = -2 cm

u = -10 cm

m = h’/h = -v/u

-2/0.5 = -v/-10

V = -40 cm

1/v + 1/u = 1/f

1/(-40) + 1/(=10) = 1/f

1/f = (-1 -4)/40

1/f = -5/40

F = -40/5

F = -8 cm

Hence the focal point will be -8 cm and the height real image of the object will be 40 cm.