Question

A 2.03 cm high insect is 1.39 m from a 131 mm focal-length lens. Where is the image? How high is it?

Answer 1

Answer:

image is 14.47 cm behind the lens

height is 2.11 mm

Explanation:

Given data

h  = 2.03 cm

p = 1.39 m = 139 cm

focal-length f = 131 mm = 13.1 cm

to find out

Where is the image and How high is it

solution

we know focal length formula that is

1/f = 1/p + 1/q

put here value to find q

1/ 13.1 = 1/ 139  + 1 solbe/ q

q =  14.463066 cm

so image is 14.47 cm behind the lens

and

height is calculate

height / h  = - q / p

put here all value

height = -14.47 / 139 × 2.03

height = −0.211324 cm

here -ve sign show image is inverted

so height is 2.11 mm