Question

an arrow 2.5 cm high is placed at a distance of 25 cm from a diverging mirror of focal length 20 centimeter. find the nature, position and size of the image formed

Answer 1

ho= 2.5cm
u= - 25cm
f= 20cm
by using mirror formula
1/f=1/v+1/u
1/v=1/f-1/u
1/v=1/20-(-1/25)
=1/20+1/25
=25+20/500
=45/500
=9/100
v=100/9
= 11.1111111cm
Image formed will be virtual and the distance of image from mirror is 11.1111111cm
Now, size of image = v/u* size of object
= 100/9*1/-25* 2.5
= - 4/9*2.5
= - 10/9cm

Answer 2

Answer:

h1 = 2.5cm

u = -25cm

f = 20cm

1/f = 1/v + 1/u

1/20 = 1/v -1/25

1/v = 1/20 + 1/25

1/v = 9/100

v = 11.11 cm

m = h2/h1 = -v/u

h2/2.5 = -11.11/-25

h2 = 1.11 cm